BEGIN:VCALENDAR
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PRODID:researchseminars.org
CALSCALE:GREGORIAN
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BEGIN:VEVENT
SUMMARY:Eske Ewert (Universität Göttingen)
DTSTART:20200527T081500Z
DTEND:20200527T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/1
DESCRIPTION:Title: Pseudodifferential calculi and generalised fixed point algebr
as\nby Eske Ewert (Universität Göttingen) as part of Göttingen Semi
nar Noncommutative Geometry\n\n\nAbstract\nIn this talk\, I will explain a
n approach to pseudo-differential calculi using generalized fixed point al
gebras.\nAs an interesting instance\, we will consider the calculus for fi
ltered manifolds that was developed by van Erp and Yuncken. Here\, vector
fields can have order higher than one when understood as differential oper
ators. This induces a “zoom”-action of the positive real numbers on th
e tangent groupoid of the filtered manifold. The C*-algebra of order zero
pseudo-differential operators can be described as a generalized fixed poin
t algebra with respect to this action.\nThis is part of my PhD project whi
ch is supervised by Prof. Ralf Meyer and Prof. Ryszard Nest.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rohan Jotz-Lean (Universität Göttingen)
DTSTART:20200603T081500Z
DTEND:20200603T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/2
DESCRIPTION:Title: Bivariant K-theory as a stable ∞-category\nby Rohan Jot
z-Lean (Universität Göttingen) as part of Göttingen Seminar Noncommutat
ive Geometry\n\n\nAbstract\nA brief introduction of ∞-categories is foll
owed by a concrete construction of a stable ∞-category that truncates to
Kasparov's bivariant K-theory. The construction is compatible with vario
us additional structures on C*-algebras (or pro-C*-algebras)\, and it has
a practical universal property that can be used\, for example\, to define
a monoidal structure.\n\nNo prior knowledge of K-theory is required.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christoph Sieling
DTSTART:20200610T081500Z
DTEND:20200610T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/3
DESCRIPTION:Title: K-theory of Cuntz-Pimsner Algebras\nby Christoph Sieling
as part of Göttingen Seminar Noncommutative Geometry\n\n\nAbstract\nThis
seminar talk presents the results of my Bachelor's thesis. We will introd
uce the notion of a C*-correspondence and construct the Toeplitz algebra b
y operators on the Fock space. Furthermore\, we define the (relative) Cun
tz-Pimsner algebra and see that it generalizes graph-C*-algebras and cross
ed products by Z. One of the main tools for computing the K-theory of thes
e algebras is the 6-term exact sequence of Pimsner. We will give the main
points of this proof.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Celso Antunes
DTSTART:20200617T081500Z
DTEND:20200617T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/4
DESCRIPTION:Title: KMS states on the groupoid model for a groupoid correspondenc
e\nby Celso Antunes as part of Göttingen Seminar Noncommutative Geome
try\n\n\nAbstract\nKMS-states are important objects of study in operator a
lgebras. In physics where operators on Hilbert spaces are used to model qu
antum systems\, KMS-states are understood as equilibrium states of the sys
tem. These ideas can be generalized to C*-algebras and in particular on th
e specific class of C*-algebras that have a groupoid model\, KMS-states re
late to quasi-invariant measures on the unit space of the groupoid model.
Groupoid correspondences are a generalization of topological graphs\, self
-similar groups and self-similar graphs. A groupoid correspondence gives r
ise to a C*-correspondence\, on which we can use the Cuntz-Pimsner constru
ction to generate a single C*-algebra. The Cuntz-Pimsner algebra for this
C*-correspondence is a C*-algebra of a groupoid\, which we call the groupo
id model for the groupoid correspondence. The unit space of this groupoid
model is still quite complicated to work with\, which makes finding quasi-
invariant measures on it also complicated. We proved that this is equivale
nt to a certain quasi-invariance relation on measures on the unit space of
the initial groupoid\, simplifying the study of these measures\, and ther
efore KMS-states for these C*-algebras.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Li Yuezhao
DTSTART:20200708T081500Z
DTEND:20200708T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/6
DESCRIPTION:Title: Coarse Mayer-Vietoris Sequence and Bulk-Edge Correspondence\nby Li Yuezhao as part of Göttingen Seminar Noncommutative Geometry\n\
n\nAbstract\nRoe C*-algebras are models of topological insulators. The bu
lk invariants are given by their K-theory. The bulk-edge correspondence c
laims that non-trivial bulk invariants lead to the existence of edge state
s. In a recent preprint\, Ludewig and Thiang constructed an integer-value
d map to compute the bulk invariants and proved that the spectral gap clos
es if the map is non-zero. They used a partition of the space\, but showe
d also that the map does not depend much on the partition.\n\nIn this talk
\, I will show that the map defined by Ludewig and Thiang agrees with a co
mposition of boundary maps in coarse Mayer-Vietoris sequences. The insens
itivity to partitions is a consequence of the naturality of the coarse May
er-Vietoris sequence. The boundary maps in coarse Mayer-Vietoris sequence
s describe the bulk-edge correspondence. These results can be generalised
to higher-dimensional spaces.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Frei (University of Copenhagen)
DTSTART:20200722T081500Z
DTEND:20200722T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/8
DESCRIPTION:Title: Gauge-invariant uniqueness theorems\, revisited\nby Alexa
nder Frei (University of Copenhagen) as part of Göttingen Seminar Noncomm
utative Geometry\n\n\nAbstract\nWe give a seemingly new and conceptual tre
atment of the gauge-invariant uniqueness theorem (in short\, gauge theorem
s) and its consequences. Its novelty is to treat all relative Cuntz-Pims
ner algebras (including and beyond Katsura's ideal) for all gauge-invarian
t representations simultaneously\, and its proof improves upon a proof by
induction due to Evgenios Kakariadis\, and reduces the problem to its hear
t: the Fell bundles.\n\nFor this\, we also separate the goal to prove the
gauge-equivariant uniqueness theorems from the task to identify kernel\, c
ovariance and associated ideal for relative Cuntz-Pimsner representations.
This separation of tasks highlights the algebraic treatment from when th
e analysis of the Fock representation becomes accomodating.\n\nIncidentall
y\, its proof renders any deeper analysis of cores completely redundant.
This includes also results beyond the gauge-equivariant uniqueness theorem
s\, as for example nuclearity or the PV six-term exact sequence.\n\nSecond
part:\nFollowing from there\, its corollaries then identify the kernel\,
covariance and associated ideal of relative Cuntz-Pimsner representations
and establish the Cuntz-Pimsner short exact sequence — now using the Foc
k representation due to the previously established gauge-equivariant uniqu
eness theorems. We will also discover obstructions here for (not necessar
ily gauge-equivariant) representations to admit any faithful embedding of
relative Cuntz-Pimsner algebras. And as another application\, we will wor
k out the detection of ideals property.\n\nOutlook:\nAs a next point\, the
speaker aims to find a more conceptual treatment of Katsura's results on
the lattice of gauge-invariant ideals\, and as a future goal\, the speaker
aims to generalise these results to product systems.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Devarshi Mukherjee (Universität Göttingen)
DTSTART:20201102T131500Z
DTEND:20201102T144500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/9
DESCRIPTION:Title: Generalised Hochschild-Kostant-Rosenberg Theorems\nby Dev
arshi Mukherjee (Universität Göttingen) as part of Göttingen Seminar No
ncommutative Geometry\n\n\nAbstract\nThe HKR theorem is a fundamental theo
rem relating Hochschild homology and de Rham cohomology. In its most basic
form\, the theorem states that for smooth commutative algebras\, Hochschi
ld homology groups are isomorphic to Kähler differentials. This result ha
s since been generalised to various non-smooth and non-affine scheme theor
etic contexts. In this talk\, I will build up from the basic HKR theorem f
or smooth algebras to recent work by Toën-Vezzosi that proves a very gene
ral version of HKR. I will conclude by mentioning an ongoing project with
Kobi Kremnizer and Jack Kelly that seeks to use Toën-Vezzosi's methods to
prove an analytic version of HKR using certain exact categories that aris
e in derived analytic geometry.\n\nI plan to make the talk accessible to a
non-commutative geometry audience and recall all relevant definitions.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jonathan Taylor (Universität Göttingen)
DTSTART:20201123T131500Z
DTEND:20201123T144500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/10
DESCRIPTION:Title: Weak Cartan inclusions following Exel and Pitts\nby Jona
than Taylor (Universität Göttingen) as part of Göttingen Seminar Noncom
mutative Geometry\n\n\nAbstract\nGiven a nice enough inclusion A into B of
C*-algebras\, can we describe B in terms of its dynamics on A? In 2008 Re
nault gave an answer to this: yes\, if the conditions are nice enough\, on
e can describe the inclusion using a twisted groupoid C*-algebraic model.
Renault called an inclusion satisfying these conditions “Cartan”. \nTh
ere have been a number of advancements in this field since then\, working
at weakening the conditions in Renault's original paper while presenting s
imilar results. In this seminar I will talk about one such paper by Exel a
nd Pitts from 2019\, working to weaken conditions on the inclusion from Re
nault's initial paper\; particularly the existence of a conditional expect
ation\, and the maximal abelian property of A.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:George Nadareishvili (Tbilisi State University)
DTSTART:20201221T131500Z
DTEND:20201221T144500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/11
DESCRIPTION:Title: Approximation of KK-theory of type I C*-algebras with finite
group actions by Mackey functors for twists\nby George Nadareishvili
(Tbilisi State University) as part of Göttingen Seminar Noncommutative Ge
ometry\n\n\nAbstract\nIn this talk\, we will modify a familiar notion of M
ackey functors from representation theory\, by extending them to encompass
projective representations of finite groups and use them to find K-theore
tic approximations of equivariant KK-theory of type I C*-algebras with fin
ite group actions.\nThis is ongoing joint work with Ralf Meyer\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Celso Antunes (Göttingen University)
DTSTART:20210111T131500Z
DTEND:20210111T144500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/12
DESCRIPTION:by Celso Antunes (Göttingen University) as part of Göttingen
Seminar Noncommutative Geometry\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jonas Luckhardt (Göttingen University)
DTSTART:20210118T131500Z
DTEND:20210118T144500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/13
DESCRIPTION:Title: Convolution of measures on locally compact groupoids\nby
Jonas Luckhardt (Göttingen University) as part of Göttingen Seminar Non
commutative Geometry\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuezhao Li (Göttingen University)
DTSTART:20210125T131500Z
DTEND:20210125T144500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/14
DESCRIPTION:Title: Bulk indices of topological insulators modelled by Roe C*-al
gebras\nby Yuezhao Li (Göttingen University) as part of Göttingen Se
minar Noncommutative Geometry\n\n\nAbstract\nRoe C*-algebras are models of
disordered topological insulators. When we consider systems with symmetri
es\, we should tensor the real or complex Roe C*-algebras with a real or c
omplex Clifford algebra\, which gives real or complex graded C*-algebras.
Their van Daele K-theory classes are called symmetry protected topological
phases\, briefly SPT. Using a partition of the space\, Roe C*-algebras ha
ve coarse Mayer-Vietoris sequences in van Daele's K-theory. The Mayer-Viet
oris boundary maps model the bulk-edge correspondences. Compositions of t
hese map an SPT phase to a Z- or Z/2-valued index.\n\nIn this talk\, we wi
ll first introduce topological insulators protected by symmetries\, and sh
ow how to use van Daele's K-theory to classify their topological phases. T
hen we use the coarse Mayer-Vietoris sequence to obtain a bulk index of SP
T phases\, and explain the Z/2-index of class AII topological insulators i
n dimension 3. In the end\, we will use tools from coarse geometry to giv
e some example where the Mayer-Vietoris boundary maps are isomorphisms.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jan Held (Göttingen University)
DTSTART:20210201T131500Z
DTEND:20210201T144500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/15
DESCRIPTION:Title: Second adjointness for reductive p-adic groups\nby Jan H
eld (Göttingen University) as part of Göttingen Seminar Noncommutative G
eometry\n\n\nAbstract\nLet $G$ be a connected reductive $\\mathfrak p$-adi
c group. A representation $\\pi \\colon G \\to \\operatorname{Aut}_k(V)$ i
s smooth if the stabliser of each vector is open in $G.$ The category of s
mooth representations of $G$ is isomorphic to the category of smooth (non-
degenerate) modules over the convolution algebra $A = \\mathcal D(G)$ of l
ocally constant\, compactly supported functions $f \\colon G \\to k.$ \n\n
If $P = MN \\subset G$ is a parabolic subgroup of $G$ with Levi subgroup $
M$ und unipotent radical $N\,$ then $M$ is again a connected reductive $\\
mathfrak p$-adic group\, and one considers the functors $r_M$ and $i_M$ of
parabolic restriction and induction\, respectively. There is a form of Fr
obenius reciprocity between these functors: $i_M$ is canonically right adj
oint to $r_M.$ It is a harmless-looking\, but deep result by J. N. Bernste
in\, called Second Adjointness\, that $i_M$ is also left adjoint to $\\bar
r_M\,$ parabolic restriction with respect to the opposite parabolic subgr
oup $\\bar P = M\\bar N.$\n\nIn this talk\, we shall recall some notions a
nd then speak about an attempt to construct a proof of Second Adjointness
by way of smooth modules.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Camila Fabre Sehnem (Victoria University of Wellington)
DTSTART:20210208T131500Z
DTEND:20210208T144500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/16
DESCRIPTION:Title: Toeplitz algebras of semigroups\nby Camila Fabre Sehnem
(Victoria University of Wellington) as part of Göttingen Seminar Noncommu
tative Geometry\n\n\nAbstract\nThe Toeplitz C*-algebra $\\mathcal{T}_\\la
mbda(P)$ of a left cancellative monoid $P$ is the C*-algebra generated by
the left regular representation of $P$ by isometries on $\\ell^2(P)$. When
a characterisation of $\\mathcal{T}_\\lambda(P)$ via a universal property
for generators and relations is possible\, and conditions are given for f
aithfulness of representations\, one obtains what is known as a uniqueness
theorem\, as in celebrated results of Coburn\, Douglas and Cuntz. Li intr
oduced a C*-algebra for an arbitrary submonoid of a group via generators a
nd relations in a far-reaching generalisation of the C*-algebras associate
d to positive cones of quasi lattice orders by Nica and of the Toeplitz-ty
pe C*-algebras associated to algebraic number fields. His C*-algebra is ca
nonically isomorphic to $\\mathcal{T}_\\lambda(P)$ for $P$ in a large clas
s of monoids\, but this is never the case if $P$ does not satisfy a certai
n independence condition. I will report on recent work with M. Laca\, in w
hich we define a universal Toeplitz C*-algebra $\\mathcal{T}_u(P)$ via gen
erators and relations that is canonically isomorphic to Li's semigroup C*-
algebra when independence holds and works as it should when independence f
ails. I will address faithfulness of representations and uniqueness theore
ms for Toeplitz C*-algebras\, presenting results that are new also for mon
oids that satisfy independence. If time permits\, I intend to give a concr
ete presentation for the covariance algebra of the canonical product syste
m over $P$ with one-dimensional fibres using a notion of foundation sets a
nd to explain why this C*-algebra may be viewed as a universal analogue of
the boundary quotient of $\\mathcal{T}_\\lambda(P)$.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geoffrey-Desmond Busche (Universität Göttingen)
DTSTART:20210505T121500Z
DTEND:20210505T134500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/17
DESCRIPTION:Title: An algebraic view on differential operators and their adjoin
ts\nby Geoffrey-Desmond Busche (Universität Göttingen) as part of G
öttingen Seminar Noncommutative Geometry\n\n\nAbstract\nA classical objec
t of interest in manifold and groupoid theory are differential operators.
This talk first introduces differential operators on manifolds in differe
nt ways\, depending more or less on the choice of coordinates. The main r
esult characterises which *-algebra structures on the algebra of different
ial operators come from the adjoint operator on the L²-space for a volume
form. In the end\, we carry this over to the algebra of invariant differ
ential operators on a Lie groupoid.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Devarshi Mukherjee (Universität Göttingen)
DTSTART:20210512T121500Z
DTEND:20210512T134500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/18
DESCRIPTION:Title: Bornological Hochschild-Kostant-Rosenberg Theorem\nby De
varshi Mukherjee (Universität Göttingen) as part of Göttingen Seminar N
oncommutative Geometry\n\n\nAbstract\nLet R be a Banach ring. We prove tha
t the category of chain complexes of complete bornological R-modules (and
several related categories) are homotopy and derived algebraic contexts in
the sense of Toen-Vezzosi and Raksit. We then use the framework of derive
d algebra to prove a general version of the HKR Theorem\, which in particu
lar relates the circle action on the Hochschild algebra to the de Rham-dif
ferential- enriched-de Rham algebra of a simplicial\, commutative\, comple
te bornological algebra. This has a geometric interpretation in the langua
ge of derived analytic geometry\, namely\, the derived loop stack of a der
ived analytic stack is equivalent to the shifted tangent stack. These obse
rvations are part of joint work-in-progress with Jack Kelly and Kobi Kremn
izer.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jonathan Taylor (Universität Göttingen)
DTSTART:20210519T121500Z
DTEND:20210519T134500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/19
DESCRIPTION:Title: Morphisms between Cartan subalgebras and their underlying tw
isted groupoids\nby Jonathan Taylor (Universität Göttingen) as part
of Göttingen Seminar Noncommutative Geometry\n\n\nAbstract\nIn his 2008 p
aper\, Renault firmly established the one-to-one correspondence between Ca
rtan pairs of C*-algebras and twisted étale Hausdorff essentially princip
al groupoids. One may then ask the question\, what are the appropriate mor
phisms to consider between such twisted groupoids to induce useful morphis
ms between Cartan pairs (or vice versa)? In this talk\, I will give some p
ossible answers to this question from the work of Li\, Buneci-Stachura\, a
nd Meyer-Zhu. Li's work shows equivalence of injective *-homomorphisms bet
ween the Cartan pairs with existence of an intermediate twisted groupoid '
between' the two Weyl groupoids. Buneci-Stachura and Meyer-Zhu introduce n
ew morphisms between categories of groupoid actions\, called 'actors'\, an
d show that these induce actions (i.e. multiplier valued *-homomorphisms)
on the corresponding groupoid C*-algebras. This can easily be extended to
twisted groupoids and their C*-algebras.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jack Kelly
DTSTART:20210526T121500Z
DTEND:20210526T134500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/20
DESCRIPTION:Title: Bornological Spectra\nby Jack Kelly as part of Göttinge
n Seminar Noncommutative Geometry\n\n\nAbstract\nIn this talk we introduce
the monoidal (infinity\,1)-category of bornological spectra. We define th
e bornological homotopy groups of bornological spectra\, and what it means
for a bornological spectrum to be complete. Following work of Durov\, Mih
ara\, and Paugam we define topological Hochschild homology and periodic cy
clic homology of bornological ring spectra\, and explain how one can globa
lise these definitions to obtain invariants of analytic spaces. This is pa
rt of work in progress with Federico Bambozzi\, Oren Ben-Bassat\, Kobi Kre
mnizer and Devarshi Mukherjee.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Oren Ben-Bassat (University of Haifa)
DTSTART:20210616T121500Z
DTEND:20210616T134500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/21
DESCRIPTION:Title: Homotopy Epimorphisms and Banach Algebraic Geometry\nby
Oren Ben-Bassat (University of Haifa) as part of Göttingen Seminar Noncom
mutative Geometry\n\n\nAbstract\nI will start by talking about homotopy ep
imorphisms of ring-ish objects in different areas of mathematics. These in
clude Kontsevich's approach to non-commutative geometry and derived and ho
motopy algebraic geometry as in the work of Lurie\, Toen and Vezzosi. From
here\, I will transition into (commutative\, derived) analytic geometry.
I will present a general form of algebraic geometry relative to the catego
ry of Banach abelian groups. I will try to give examples of interest in co
mplex and p-adic analytic geometry\, and even to an analytic viewpoint on
arithmetic geometry.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Taeyoung Lee (Universität Göttingen)
DTSTART:20210908T101500Z
DTEND:20210908T114500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/22
DESCRIPTION:Title: A bicategorical view on group actions on rings\nby Taeyo
ung Lee (Universität Göttingen) as part of Göttingen Seminar Noncommuta
tive Geometry\n\n\nAbstract\nIn this talk\, We will consider the bicategor
y $\\mathfrak{Rings}$ which has rings as objects\, $S\,R$-bimodules as arr
ows $S \\leftarrow R$\, and bimodule maps between them as 2-arrows. We dis
cuss a generalization of a twisted group action on a ring as a homomorphis
m $G \\rightarrow \\mathfrak{Rings} $ and its lax and strong covariance ri
ngs. \nWe also provide few examples of strong covariance rings for some mo
rphisms $(\\mathbb{N}\,+) \\rightarrow \\mathfrak{Rings}$. The main idea i
s constructing a directed graph from the given morphism. The Leavitt path
algebra of such directed graph is closely related with the strong covarian
ce ring.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Boris Bilich (Universität Göttingen)
DTSTART:20211027T081500Z
DTEND:20211027T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/23
DESCRIPTION:Title: Noncommutative holomorphic functional calculus for double co
verings\nby Boris Bilich (Universität Göttingen) as part of Götting
en Seminar Noncommutative Geometry\n\n\nAbstract\nLet $T$ be a bounded ope
rator on a Banach space $X$. Let $U$ be a neighborhood of the spectrum of
$T$. The classical holomorphic functional calculus theorem asserts that th
ere is a unique continuous algebra homomorphism from the algebra of holomo
rphic functions $\\mathcal{O}(U)$ to the algebra of bounded operators on $
X$ such that the coordinate function $z$ maps to $T$. In 1970\, Taylor ext
ended this result to tuples of commuting bounded operators and holomorphic
functions in several variables. In later works by several authors there w
ere attempts to generlazie the functional calculus to non-commuting tuples
of operators or\, more generally\, to Banach representations of associati
ve algebras. \n\nIn the talk\, I will associate a non-commutative algebra
to a double covering of a complex domain. One particular example of such a
lgebra would be a group algebra of the infinite dihedral group. Then\, I w
ill introduce a structure of non-Hausdorff complex space on the primitive
spectrum of this algebra and endow it with a presheaf of noncommutative al
gebras\, which will play a role of noncommutative holomorphic functions. I
will define a spectrum and prove the noncommutative functional calculus t
heorem. I will also prove a version of the spectral mapping theorem.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geoffrey-Desmond Busche (Universität Göttingen)
DTSTART:20211103T091500Z
DTEND:20211103T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/24
DESCRIPTION:Title: Dimension\, decomposability and nuclear C*-algebras\nby
Geoffrey-Desmond Busche (Universität Göttingen) as part of Göttingen Se
minar Noncommutative Geometry\n\n\nAbstract\nIn this talk I give a short i
ntroduction to covering dimension of (separable\, metrisable) topological
spaces as defined by Hurewicz/Wallman in 1948. An important part is the De
composability Theorem\, which states that every finite open cover of an n-
dimensional space has an n-decomposable refinement. I give a modern proof
of the Decomposability Theorem using simplicial complices\, following a pa
per by Kichberg/Winter. With respect to the same paper I compare topologic
al covering dimension to decomposition rank in C*-algebras.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Devarshi Mukherjee (Universität Göttingen)
DTSTART:20211110T091500Z
DTEND:20211110T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/25
DESCRIPTION:Title: Local cyclic cohomology\nby Devarshi Mukherjee (Universi
tät Göttingen) as part of Göttingen Seminar Noncommutative Geometry\n\n
\nAbstract\nLet $V$ be a complete discrete valuation ring with uniformiser
$\\pi$\, residue field $k = V/\\pi V$\, and fraction field $F$. In this t
alk\, I will introduce an invariant of Banach $V$-algebras called local cy
clic cohomology. This invariant is related to analytic cyclic homology for
complete\, bornologically torsion-free $V$-algebras. As a consequence of
its definition and the formal properties of analytic cyclic homology\, it
will be shown that local cyclic homology only depends on the reduction mod
\\(\\pi\\) of the original Banach \\(V\\)-algebra. Furthermore\, the inva
riant we define satisfies homotopy invariance\, matricial stability and ex
cision. This is joint work with Joachim Cuntz and Ralf Meyer.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ralf Meyer (Universität Göttingen)
DTSTART:20211117T091500Z
DTEND:20211117T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/26
DESCRIPTION:Title: Classification of non-simple graph C*-algebras\nby Ralf
Meyer (Universität Göttingen) as part of Göttingen Seminar Noncommutati
ve Geometry\n\n\nAbstract\nI speak about a project with Rasmus Bentmann th
at I started some time ago and plan to complete in the coming weeks. The
goal is to classify graph C*-algebras\, whether simple or not\, up to isom
orphism\, using an invariant that contains the ideal structure and the K-t
heory of suitable ideals\, together with an obstruction class. The proof
method is rather elementary. We describe correspondences from a graph C*-
algebra to another C*-algebra B using projections in the stabilisation of
B and certain unitaries in suitable corners of the stabilisation of B. Up
to homotopy\, we can classify these correspondences and show that a pair
of maps on a K₀- and K₁-like invariant lifts if and only if a certain
homological obstruction in an Ext²-group vanishes. As of now\, the metho
d gives classification up to isomorphism for graph C*-algebras that are ei
ther purely infinite or AF but need not be simple\, and classification up
to homotopy equivalence in general.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jonathan Taylor (Universität Göttingen)
DTSTART:20211124T091500Z
DTEND:20211124T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/27
DESCRIPTION:Title: An analogue of the local multiplier algebra for Hilbert modu
les\nby Jonathan Taylor (Universität Göttingen) as part of Göttinge
n Seminar Noncommutative Geometry\n\n\nAbstract\nGiven a C*-algebra A\, on
e can construct the local multiplier algebra of A into which the multiplie
r algebras of all ideals of A embed. This allows one to define maps from o
ther C*-algebras into the local multiplier algebra of A by specifying how
elements may act on an ideal of A\, in particular one gains a larger suite
of generalised conditional expectations to work with (among other things)
. In this talk I shall show an analogous construction of the local multipl
ier algebra for Hilbert modules\, and how one can enrich actions by Hilber
t bimodules on A to actions on the local multiplier algebra of A. One appl
ication of this is to enrich an inclusion of C*-algebras that is not quite
Cartan\, into a Cartan inclusion.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Becky Armstrong (Westfälische Wilhelms-Universität Münster)
DTSTART:20211222T091500Z
DTEND:20211222T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/28
DESCRIPTION:Title: Twisted C*-algebras of Deaconu–Renault groupoids\nby B
ecky Armstrong (Westfälische Wilhelms-Universität Münster) as part of G
öttingen Seminar Noncommutative Geometry\n\n\nAbstract\nIn 2014\, Brown\,
Clark\, Farthing\, and Sims proved that the C*-algebra of an amenable Hau
sdorff étale groupoid is simple if and only if the groupoid is minimal an
d effective. This result does not hold for the more general class of $\\te
xtit{twisted}$ groupoid C*-algebras\, because\, for instance\, the irratio
nal rotation algebras are simple twisted C*-algebras of non-effective grou
poids. In 2015\, Kumjian\, Pask\, and Sims used groupoid techniques to giv
e a characterisation of simplicity of twisted C*-algebras of cofinal\, row
-finite\, source-free higher-rank graphs. The groupoids involved belong to
the strictly larger class of $\\textit{Deaconu--Renault groupoids}$. In t
his talk\, I will give a characterisation of simplicity of twisted C*-alge
bras of all ($\\mathbb{Z}^k$-graded) Deaconu–Renault groupoids. (This is
joint work with Nathan Brownlowe and Aidan Sims.)\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Markus Obendrauf (Universität Göttingen)
DTSTART:20220112T091500Z
DTEND:20220112T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/29
DESCRIPTION:Title: Classification of 2-groups using skeleta\nby Markus Oben
drauf (Universität Göttingen) as part of Göttingen Seminar Noncommutati
ve Geometry\n\n\nAbstract\nCrossed modules are generalised groups\, and cr
ossed module actions are generalised group actions. Crossed modules are al
so the same as strict 2-groups\, a structure arising in category theory. W
e use the tools of (bi-)category theory to classify 2-groups and crossed m
odules up to equivalence.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Collin Mark Joseph (Universität Göttingen)
DTSTART:20220126T091500Z
DTEND:20220126T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/30
DESCRIPTION:Title: Geometric Construction of Hamiltonians\nby Collin Mark J
oseph (Universität Göttingen) as part of Göttingen Seminar Noncommutati
ve Geometry\n\n\nAbstract\nWe compute a particular generator of the KR-the
ory of the d-torus using the geometric picture of bivariant KK-theory. We
use Van Daele's K-theory to describe explicit generators for the K-theory
of the spheres.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Taufik Yusof (Universität Göttingen)
DTSTART:20220209T091500Z
DTEND:20220209T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/31
DESCRIPTION:Title: Category of modules and (classical) Morita theory\nby Ta
ufik Yusof (Universität Göttingen) as part of Göttingen Seminar Noncomm
utative Geometry\n\n\nAbstract\nWe revisit the classical Morita theory for
unital rings and outline the sketch of the proof. We then talk about alte
rnative(s) to categories of modules in the literatures\, suggesting a vers
ion of Morita theory for the non-unital case may be made possible.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Apurva Seth (IISER Bhopal)
DTSTART:20220119T091500Z
DTEND:20220119T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/32
DESCRIPTION:Title: Nonstable $K$-Theory for $C^*$-Algebras\nby Apurva Seth
(IISER Bhopal) as part of Göttingen Seminar Noncommutative Geometry\n\n\n
Abstract\nNonstable K-theory is the study of the homotopy groups of the gr
oup of (quasi-) unitaries of a $C^*$-algebra. We will give an overview of
the theory and discuss a special class of $C^*$-algebras termed as $K$-sta
ble $C^*$-algebras along with its rational analogue. We shall give a perma
nence property related to $K$-stability (rational $K$-stability) concernin
g continuous $C(X)$-algebras. We will end with a procedure to compute the
rational nonstable $K$-groups for AF-algebras along with some results on t
heir $K$-stability.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mohammed Amir (IISER Bhopal)
DTSTART:20220202T091500Z
DTEND:20220202T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/33
DESCRIPTION:Title: KMS states on the C*-algebra of a Fell bundle over an étale
groupoid\nby Mohammed Amir (IISER Bhopal) as part of Göttingen Semin
ar Noncommutative Geometry\n\n\nAbstract\nFirstly\, we will discuss how to
define the full $\\textrm{C}^*$-algebra of an {\\'e}tale groupoid. After
that\, we will state Neshveyev's theorem which characterises the KMS state
s on the $\\textrm{C}^*$-algebra of an {\\'e}tale groupoid when the dynami
cs is given by a real-valued one cocycle. Then we will discuss our general
isation of the Neshveyev's theorem for the full $\\textrm{C}^*$-algebra of
a Fell bundle over an {\\'e}tale groupoid. And finally\, we will discuss
one application of our result.\n\nMeeting ID: 958 7370 6
690\nPasscode: 295706\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Guo Chuan Thiang (Peking University\, Beijing\, China)
DTSTART:20211208T091500Z
DTEND:20211208T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/34
DESCRIPTION:Title: Gerbes\, topological insulators\, and quaternionic operator
K-theory\nby Guo Chuan Thiang (Peking University\, Beijing\, China) as
part of Göttingen Seminar Noncommutative Geometry\n\n\nAbstract\nRecentl
y\, physicists discovered that the boundary spectrum of a topological insu
lator is totally gapless in a perturbation-resistant way (mod 2). The math
ematics underlying this remarkable phenomenon involves K-theory and index
theory for operator algebras\, as well as the geometrical idea of gerbes f
or the spectral interpretation. Importantly\, it takes place in the real/q
uaternionic (rather than complex) setting\, which is largely unexplored te
rritory potentially hiding a wealth of interesting mathematics.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ralf Meyer (Universität Göttingen)
DTSTART:20211201T091500Z
DTEND:20211201T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/35
DESCRIPTION:Title: The bicategory of groupoid correspondences\nby Ralf Meye
r (Universität Göttingen) as part of Göttingen Seminar Noncommutative G
eometry\n\n\nAbstract\nWe define a bicategory with étale\, locally compac
t groupoids as objects and suitable correspondences\, that is\, spaces wit
h two commuting actions as arrows\; the 2-arrows are injective\, equivaria
nt continuous maps. We prove that the usual recipe for composition makes
this a bicategory\, carefully treating also non-Hausdorff groupoids and co
rrespondences. We extend the groupoid C*-algebra construction to a homomo
rphism from this bicategory to that of C*-algebra correspondences. We des
cribe the C*-algebras of self-similar groups\, higher-rank graphs\, and di
screte Conduché fibrations in our setup.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Devarshi Mukherjee (Universität Göttingen)
DTSTART:20211215T091500Z
DTEND:20211215T104500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/36
DESCRIPTION:Title: Isocohomological embeddings and Hochschild homology\nby
Devarshi Mukherjee (Universität Göttingen) as part of Göttingen Seminar
Noncommutative Geometry\n\n\nAbstract\nWe study the interaction between v
arious analytification functors\,\nand a class of morphisms of rings\, cal
led homotopy epimorphisms. An analytifi-\ncation functor assigns to a simp
licial commutative algebra over a ring \\(R\\)\, along\nwith a choice of B
anach structure on \\(R\\)\, a commutative monoid in the monoidal\nmodel c
ategory of simplicial ind-Banach \\(R\\)-modules. We show that several\nan
alytifications relevant to analytic geometry - such as Tate\, overconverge
nt\,\nStein analytification\, and formal completion - are homotopy epimorp
hisms.\nAnother class of examples of homotopy epimorphisms arises from Wei
erstrass\,\nLaurent and rational localizations in derived analytic geometr
y. As applications\nof this result\, we prove that Hochschild homology and
the cotangent complex\nare computable for analytic rings\, and the comput
ation relies only on known\ncomputations of Hochschild homology for polyno
mial rings. We show that in\nvarious senses\, Hochschild homology as we de
fine it commutes with localizations\,\nanalytifications and completions. T
his is joint work with Oren Ben-Bassat.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hao Xu (Universität Göttingen)
DTSTART:20220427T081500Z
DTEND:20220427T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/37
DESCRIPTION:by Hao Xu (Universität Göttingen) as part of Göttingen Semi
nar Noncommutative Geometry\n\nLecture held in Sitzungssaal at Mathematisc
hes Institut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hao Xu (Universität Göttingen)
DTSTART:20220504T081500Z
DTEND:20220504T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/38
DESCRIPTION:by Hao Xu (Universität Göttingen) as part of Göttingen Semi
nar Noncommutative Geometry\n\nLecture held in Sitzungssaal at Mathematisc
hes Institut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ali Imad Raad (KU Leuven)
DTSTART:20220511T081500Z
DTEND:20220511T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/39
DESCRIPTION:Title: Constructing Cartan Subalgebras in Inductive Limit C*-algebr
as\nby Ali Imad Raad (KU Leuven) as part of Göttingen Seminar Noncomm
utative Geometry\n\nLecture held in Sitzungssaal at Mathematisches Institu
t\, Göttingen.\n\nAbstract\nThe concept of Cartan subalgebras in C*-algeb
ras has in recent years attracted attention due to its connections to geom
etric group theory and topological dynamics\, as well as important connect
ions to the classification programme for C*-algebras. A relatively unexplo
red area is that of how to build Cartan subalgebras in inductive limit C*-
algebras from Cartan subalgebras in the building blocks. In this talk\, we
will explore this area and give some recent existence results in certain
classes of inductive limits. We will also address the question of uniquene
ss of such Cartan subalgebras. This talk is based on the results of my PhD
\, as well as recent joint work with Xin Li.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jan Held (Universität Göttingen)
DTSTART:20220713T081500Z
DTEND:20220713T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/40
DESCRIPTION:Title: Bernstein's Second Adjunction Theorem\nby Jan Held (Univ
ersität Göttingen) as part of Göttingen Seminar Noncommutative Geometry
\n\nLecture held in Sitzungssaal at Mathematisches Institut\, Göttingen.\
nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Celso Antunes (Universität Göttingen)
DTSTART:20220720T081500Z
DTEND:20220720T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/41
DESCRIPTION:Title: C*-Algebras of relatively proper groupoid correspondences\nby Celso Antunes (Universität Göttingen) as part of Göttingen Semina
r Noncommutative Geometry\n\nLecture held in Sitzungssaal at Mathematische
s Institut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jonathan Taylor (Universität Göttingen)
DTSTART:20220601T081500Z
DTEND:20220601T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/42
DESCRIPTION:Title: Inductive limits of noncommutative aperiodic Cartan inclusio
ns\nby Jonathan Taylor (Universität Göttingen) as part of Göttingen
Seminar Noncommutative Geometry\n\nLecture held in Sitzungssaal at Mathem
atisches Institut\, Göttingen.\n\nAbstract\nIn 2008 Renault proved that c
ommutative Cartan pairs are given by twisted groupoid C*-algebras. In 2018
Li used these groupoid models to construct commutative Cartan subalgebras
in inductive limit C*-algebras\, where each building block C*-algebra has
a commutative Cartan subalgebra and the connecting morphisms preserve all
of the relevant Cartan structure.\nWe generalise this result to inductive
limits where the building blocks may be noncommutative aperiodic Cartan p
airs\, showing that the inductive limit will again be a noncommutative Car
tan pair. We give some conditions under which the inductive limit pair is
also an aperiodic inclusion. Our proof is purely C*-algebraic without pass
ing to groupoids\, so in particular generalises Li's proof.\nThese results
are joint work with Ralf Meyer and Ali Imad Raad.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ralf Meyer (Universität Göttingen)
DTSTART:20221027T081500Z
DTEND:20221027T094500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/44
DESCRIPTION:Title: Representations of *-algebras by unbounded operators: Plan o
f the semester\nby Ralf Meyer (Universität Göttingen) as part of Gö
ttingen Seminar Noncommutative Geometry\n\nLecture held in Sitzungssaal at
Mathematisches Institut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/44/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michelle Göbel (Universität Göttingen)
DTSTART:20221103T111500Z
DTEND:20221103T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/45
DESCRIPTION:Title: Covariance algebras for actions of locally compact groups on
C*- algebras\nby Michelle Göbel (Universität Göttingen) as part of
Göttingen Seminar Noncommutative Geometry\n\nLecture held in Sitzungssaa
l at Mathematisches Institut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Taufik Yusof (Universität Göttingen)
DTSTART:20221110T111500Z
DTEND:20221110T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/46
DESCRIPTION:Title: Hilbert modules and C*-correspondences\nby Taufik Yusof
(Universität Göttingen) as part of Göttingen Seminar Noncommutative Geo
metry\n\nLecture held in Sitzungssaal at Mathematisches Institut\, Göttin
gen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Kern (Universität Göttingen)
DTSTART:20221124T111500Z
DTEND:20221124T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/47
DESCRIPTION:Title: The functional calculus and its converse for regular selfa
djoint operators\nby David Kern (Universität Göttingen) as part of G
öttingen Seminar Noncommutative Geometry\n\nLecture held in Sitzungssaal
at Mathematisches Institut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jonathan Taylor (Universität Göttingen)
DTSTART:20221222T111500Z
DTEND:20221222T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/48
DESCRIPTION:Title: When the C*-hull is a (twisted) groupoid C*-algebra\nby
Jonathan Taylor (Universität Göttingen) as part of Göttingen Seminar No
ncommutative Geometry\n\nLecture held in Sitzungssaal at Mathematisches In
stitut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/48/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ralf Meyer (Universität Göttingen)
DTSTART:20230202T111500Z
DTEND:20230202T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/49
DESCRIPTION:Title: More examples of C*-hulls of *-algebras\nby Ralf Meyer (
Universität Göttingen) as part of Göttingen Seminar Noncommutative Geom
etry\n\nLecture held in Sitzungssaal at Mathematisches Institut\, Götting
en.\n\nAbstract\nI will present some more examples of C*-hulls constructed
by Dowerk\, Savchuk\, Schmüdgen using the induction theorem for C*-hulls
.\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/49/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christos Kitsios (Universität Göttingen)
DTSTART:20221117T111500Z
DTEND:20221117T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/50
DESCRIPTION:Title: Representations of *-algebras on Hilbert modules by unboun
ded operators\nby Christos Kitsios (Universität Göttingen) as part o
f Göttingen Seminar Noncommutative Geometry\n\nLecture held in Sitzungssa
al at Mathematisches Institut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/50/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Boris Bilich (Universität Göttingen)
DTSTART:20221201T111500Z
DTEND:20221201T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/51
DESCRIPTION:Title: Nelson’s Theorem\nby Boris Bilich (Universität Götti
ngen) as part of Göttingen Seminar Noncommutative Geometry\n\nLecture hel
d in Sitzungssaal at Mathematisches Institut\, Göttingen.\nAbstract: TBA\
n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/51/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michelle Göbel (Universität Göttingen)
DTSTART:20221208T111500Z
DTEND:20221208T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/52
DESCRIPTION:Title: Graded algebras and induction of representations and C*-hull
s\nby Michelle Göbel (Universität Göttingen) as part of Göttingen
Seminar Noncommutative Geometry\n\nLecture held in Sitzungssaal at Mathema
tisches Institut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/52/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michelle Göbel (Universität Göttingen)
DTSTART:20221215T111500Z
DTEND:20221215T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/53
DESCRIPTION:Title: Graded algebras and induction of representations and C*-hull
s\nby Michelle Göbel (Universität Göttingen) as part of Göttingen
Seminar Noncommutative Geometry\n\nLecture held in Sitzungssaal at Mathema
tisches Institut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/53/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ralf Meyer (Universität Göttingen)
DTSTART:20230112T111500Z
DTEND:20230112T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/54
DESCRIPTION:Title: Some examples of C*-hulls: twisted Weyl algebras\nby Ral
f Meyer (Universität Göttingen) as part of Göttingen Seminar Noncommuta
tive Geometry\n\nLecture held in Sitzungssaal at Mathematisches Institut\,
Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/54/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fabrizio Zanello (Universität Göttingen)
DTSTART:20230119T111500Z
DTEND:20230119T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/55
DESCRIPTION:Title: Host algebras for actions of topological groups\nby Fabr
izio Zanello (Universität Göttingen) as part of Göttingen Seminar Nonco
mmutative Geometry\n\nLecture held in Sitzungssaal at Mathematisches Insti
tut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/55/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lennart Janshen (Universität Göttingen)
DTSTART:20230126T111500Z
DTEND:20230126T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/56
DESCRIPTION:Title: Host algebras for infinite-dimensional Lie groups\nby Le
nnart Janshen (Universität Göttingen) as part of Göttingen Seminar Nonc
ommutative Geometry\n\nLecture held in Sitzungssaal at Mathematisches Inst
itut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/56/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geoffrey Desmond-Busche (Universität Göttingen)
DTSTART:20230216T111500Z
DTEND:20230216T124500Z
DTSTAMP:20260404T111249Z
UID:GoettingenNCG/57
DESCRIPTION:Title: The *-algebra of differential operators on a manifold\nb
y Geoffrey Desmond-Busche (Universität Göttingen) as part of Göttingen
Seminar Noncommutative Geometry\n\nLecture held in Sitzungssaal at Mathema
tisches Institut\, Göttingen.\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/GoettingenNCG/57/
END:VEVENT
END:VCALENDAR