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BEGIN:VEVENT
SUMMARY:Àngel Joaniquet Tukiainen (Zitro)
DTSTART:20201209T110000Z
DTEND:20201209T120000Z
DTSTAMP:20260404T110830Z
UID:SIMBa/1
DESCRIPTION:Title: Relationship between victorian eugenecists and slot machine free-game
- Branching Processes\nby Àngel Joaniquet Tukiainen (Zitro) as part
of Barcelona Mathematics Informal Seminar (SIMBa)\n\n\nAbstract\nOriginaly
\, the first branching processes where studied to ensure the survival of s
urnames on Victorian\nEra aristocrat familes. These use is actually futile
as insuficient data\, changing laws or simply name\nchanges (ask Victoria
's grandson\, Edward) make this idealization irrelevant. Since then\, bran
ching\nprocesses have found uses beyond surnames\, like studing general re
porduction\, or neutron counts on\nnuclear reactions.\nIn this talk we wil
l present multi-type branching proceses and how they can be used to model
and\ncontrol populations of germs (or how to know if a slot machine is goo
d).\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:María Cumplido Cabello (Universidad Complutense de Madrid)
DTSTART:20201216T110000Z
DTEND:20201216T120000Z
DTSTAMP:20260404T110830Z
UID:SIMBa/2
DESCRIPTION:Title: Strand diagrams and generalised braided Thompson's groups\nby Mar
ía Cumplido Cabello (Universidad Complutense de Madrid) as part of Barcel
ona Mathematics Informal Seminar (SIMBa)\n\n\nAbstract\nThis is a joint wo
rk with Julio Aroca. There is a generalisation of Thompson's groups constr
ucted from the Thompson's group $V$ and Artin's braid group. The braided T
hompson's group $BV_2$ was independently introduced by Patrick Dehornoy a
nd Matthew G. Brin in 2006. In this talk we will explain how two extend th
is concept to a much bigger family of groups by using infinite braids: Inf
initely braided Thompson's groups $BV_n(H)$\, where $H$ is a subgroup of t
he braid group on $n$ strands. We will prove that they are indeed groups b
y using braided diagrams and rewriting systems. We will also see that they
are finitely generated if $H$ is finitely generated and give an explicit
set of generators for $BV_n(H)$ and some other cases. Slides will be in En
glish and the talk will be given in Spanish.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rosalba García Millán (University of Cambridge)
DTSTART:20210113T110000Z
DTEND:20210113T120000Z
DTSTAMP:20260404T110830Z
UID:SIMBa/3
DESCRIPTION:Title: Time-dependent branching processes: a model of oscillating neuronal a
valanches\nby Rosalba García Millán (University of Cambridge) as par
t of Barcelona Mathematics Informal Seminar (SIMBa)\n\n\nAbstract\nRecentl
y\, neuronal avalanches have been observed to display oscillations\, a phe
nomenon regarded as the co-existence of a scale-free behaviour (the avalan
ches close to criticality) and scale-dependent dynamics (the oscillations)
[1]. Ordinary continuous-time branching processes with constant extinctio
n and branching rates are commonly used as models of neuronal activity\, y
et they lack any such time-dependence. In my talk\, I will show how we ext
ended a basic branching process by allowing the extinction rate to oscilla
te in time as a new model to describe cortical dynamics [2]. I will discus
s about some observables\, such as the avalanche shape\, that we calculate
d in closed form by means of a perturbative field theory\, and compared to
available experimental results.\n\n[1] Miller\, Yu & Plenz\, Sci. Rep. 9\
, 16403 (2019).\n\n[2] Pausch\, Garcia-Millan & Pruessner\, Sci. Rep. 10\,
13678 (2020).\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marco Praderio Bova (Lancaster University)
DTSTART:20210127T110000Z
DTEND:20210127T120000Z
DTSTAMP:20260404T110830Z
UID:SIMBa/4
DESCRIPTION:Title: Persistent homology and barcode distance\nby Marco Praderio Bova
(Lancaster University) as part of Barcelona Mathematics Informal Seminar (
SIMBa)\n\n\nAbstract\nPersistent homology is an algebraic topology tool th
at has gained a lot of relevance in topological data analysis during the p
ast few years. During this lecture we will introduce this concept from a c
ategorical point of view and use category theory techniques in order to pr
oove what is known as stability theorem.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jose Brox (Centre for Mathematics\, University of Coimbra)
DTSTART:20210210T110000Z
DTEND:20210210T120000Z
DTSTAMP:20260404T110830Z
UID:SIMBa/5
DESCRIPTION:Title: Identities in prime rings\nby Jose Brox (Centre for Mathematics\,
University of Coimbra) as part of Barcelona Mathematics Informal Seminar
(SIMBa)\n\n\nAbstract\nGiven a ring\, a generalized polynomial identity (G
PI) is a polynomial\nidentity in which the coefficients can be taken from
the ring. Prime rings\nare a class of rings very well suited to manage pro
blems related to\nidentities\, as for example those coming from Herstein's
theory\, which is\nthe study of nonassociative objects and structures ari
sing from\nassociative rings. After a motivating introduction to prime rin
gs\, with\nsome examples from Herstein's theory\, I will show the usefulne
ss of\nMartindale's lemma\, the key tool for solving GPIs in one variable
in prime\nrings\, and I will explain a new promising approach to solve the
m based on\nelementary algebraic geometry which avoids some shortcomings o
f the lemma\,\nallowing to find the optimal solutions.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fabio Ferri (University of Exeter)
DTSTART:20210310T110000Z
DTEND:20210310T120000Z
DTSTAMP:20260404T110830Z
UID:SIMBa/6
DESCRIPTION:Title: How far is an extension of $p$-adic fields from having a normal integ
ral basis?\nby Fabio Ferri (University of Exeter) as part of Barcelona
Mathematics Informal Seminar (SIMBa)\n\n\nAbstract\nLet $L/K$ be a Galois
extension of $p$-adic \nfields with Galois group $G$. Denote by $K[G]$ th
e group ring $\\{\\sum_{g\\in G}a_gg\\\,\\colon\\\,a_g\\in K\\}$\; the cla
ssical normal basis theorem shows that $L$ is a free $K[G]$-module of rank
$1$\, that is\, there exists an element $\\alpha\\inL$ such that\n$\\{g(\
\alpha)\\}_{g\\in G}$ is a basis of $L$ as a $K$-vector space. It is natur
al to ask whether $\\mathcal{O}_L$ is also a free $\\mathcal{O}_K[G]$-modu
le of rank $1$\, where $\\mathcal{O}_L$ and $\\mathcal{O}_K$ denote the ri
ngs of integers of $L$ and $K$\, respectively. A theorem of Noether tells
us that this is the case if and only if the extension is (at most) tamely
rami\ned. When $L/K$ is wildly rami\ned\, we can still note that there alw
ays exists a free $\\mathcal{O}_K[G]$-submodule of $\\mathcal{O}L$ with \n
finite index. The purpose of this talk is to study the minimal such index\
, i.e. the quantity $m(L/K) \\coloneqq min{\\alpha\\in\\mathcal{O}_L}[\\ma
thcal{O}_L : \\mathcal{O}_K[G]\\alpha]$. We will provide a general bound t
hat only depends on the invariants of the extension\, a complete formula f
or $m(L/K)$ when $L/\\mathbb{Q}_p$ is abelian and a complete formula when
$L/K$ is cyclic of degree $p$. This is joint work with Ilaria Del Corso an
d Davide Lombardo.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Damian Dabrowsk (University of Jyväskylä)
DTSTART:20210324T110000Z
DTEND:20210324T120000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/7
DESCRIPTION:Title: On measures\, projections\, and measures of projections\nby Damia
n Dabrowsk (University of Jyväskylä) as part of Barcelona Mathematics In
formal Seminar (SIMBa)\n\n\nAbstract\nIn this talk we will look at the fol
lowing question: given a subset ofthe plane\, what is the relation
between the size of the set and thesize of its orthogonal projectio
ns? To make the notion of “size” moreprecise\, I will first explain w
hat the Hausdorff measures and the Haus-dorff dimension are. The talk sho
uld be accessible to anyone who hascompleted a basic calculus course.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eduard Soto Ballesteros (Universitat de Barcelona)
DTSTART:20210407T100000Z
DTEND:20210407T110000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/8
DESCRIPTION:Title: Coeficients de Fourier al p-èsim intèrval de Ramanujan-Petersson\nby Eduard Soto Ballesteros (Universitat de Barcelona) as part of Barcel
ona Mathematics Informal Seminar (SIMBa)\n\n\nAbstract\nL'expansió de Fou
rier d'una forma modular nova de pes 2 i caràcter trivial \nés una sèri
e de potències amb coeficients enters algebraics en un cos totalment \nre
al. Els coeficients d'índex primer tenen un rol protagonista per motius d
iversos. \nLa conjectura de Ramanujan-Petersson\, demostrada por Deligne\,
prediu que el p-èsim \ncoeficient de Fourier d'una forma modular de pes
2 té norma en $[ 0\, 2 \\sqrt{p} ]$. \nEn aquesta xerrada discutirem quin
s cossos totalment reals tenen elements primitius \nenters en $[0\, 2 \\sq
rt{p}]$. Aquest treball en colaboración amb Samuele Anni té orígens\nen
un estudi computacional d'una conjetura de Coleman.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marta Sánchez Pavón (Universidad de Sevilla)
DTSTART:20210421T100000Z
DTEND:20210421T110000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/9
DESCRIPTION:Title: Entering the tower with Iwasawa theory\nby Marta Sánchez Pavón
(Universidad de Sevilla) as part of Barcelona Mathematics Informal Seminar
(SIMBa)\n\n\nAbstract\nProving Fermat Last Theorem has been one of the mo
st famous math-ematical challenges during the last years. Most importantl
y\, it servedas a key starting point for developing deep theories in arith
metic ge-ometry\; and Iwasawa theory has been one of such. The fundamenta
lidea of Iwasawa theory is studying the growth of arithmetic obj
ects(such as the ideal class group of number fields or Selmer g
roups ofelliptic curves and abelian varieties) in an infinite tower ofp-a
dic ex-tensions. Furthermore\, much of the recent progress in the Birch a
ndSwinnerton-Dyer conjecture is due to these methods. In this talk\, wepr
esent a brief introduction to Iwasawa theory with an eye on ellipticcurves
.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Raffaele Carbone
DTSTART:20210505T100000Z
DTEND:20210505T110000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/10
DESCRIPTION:by Raffaele Carbone as part of Barcelona Mathematics Informal
Seminar (SIMBa)\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Guillem Garcia Tarrach
DTSTART:20210519T100000Z
DTEND:20210519T110000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/11
DESCRIPTION:Title: p-adic modular forms: why do we care?\nby Guillem Garcia Tarrach
as part of Barcelona Mathematics Informal Seminar (SIMBa)\n\n\nAbstract\n
Since their introduction in the seventies\, p-adic modular forms have beco
me an important topic in algebraic number theory and have seen many applic
ations to problems in this area. In this talk I will be explaining some of
the motivation for p-adic modular forms and talk about some of the import
ant results in the theory.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eloi Torrent Juste
DTSTART:20210602T100000Z
DTEND:20210602T110000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/12
DESCRIPTION:Title: An introduction to theorem provers\nby Eloi Torrent Juste as par
t of Barcelona Mathematics Informal Seminar (SIMBa)\n\n\nAbstract\nIn thi
s talk\, we will introduce proof assistants\, pieces of softwaret
hat formally verify mathematical proofs.Lean has a very extensived
atabase with mathematical results at the undergraduate level for-m
ally verified\, and it is even used to verify new research. Th
is hasseveral applications\, including teaching\, automatically verifying
publi-cations\, and even automated theorem proving. At the end of this t
alk\,we will carry out a demo of Lean to show the basics and how you cange
t started.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Gil Muñoz (Charles University in Prague)
DTSTART:20211006T100000Z
DTEND:20211006T110000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/13
DESCRIPTION:Title: On the possible ranks of universal quadratic forms over totally real
number fields\nby Daniel Gil Muñoz (Charles University in Prague) as
part of Barcelona Mathematics Informal Seminar (SIMBa)\n\n\nAbstract\nA q
uadratic form $Q(X_1\,...\,X_n)$ over the integer numbers is said to be un
iversal if it represents all positive integers\, that is\, for every $a \\
in \\mathbb{Z}>0$ there is a vector $(\\alpha_1\,...\,\\alpha_n)\\in \\mat
hbb{Z}^n$ such that $Q(\\alpha_1\,...\,\\alpha_n) = a$. The topic of unive
rsal quadratic forms is quite classical in arithmetic\; for instance\, Lag
range's 1770 four square theorem asserts that the sum of four squares is a
universal quadratic form over $\\mathbb{Z}$. \nIn this talk\, we consider
the suitable generalization of universality for quadratic forms over the
number ring $\\mathcal{O}_K$ of a totally real number field $K$ and view s
ome recent results on the possible ranks (number of variables $X_i$) of un
iversal quadratic forms over different families of totally real number\nfi
elds.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Gil Muñoz (University of Barcelona)
DTSTART:20231004T110000Z
DTEND:20231004T120000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/14
DESCRIPTION:Title: The use of skew braces in Hopf-Galois theory\nby Daniel Gil Muñ
oz (University of Barcelona) as part of Barcelona Mathematics Informal Sem
inar (SIMBa)\n\nLecture held in UPC (FME aula 005).\n\nAbstract\nThe notio
n of Galois extension can be rewritten in such a way that it depends only
on the Galois group and its action on the top field of the extension. More
over\, the group algebra corresponding to the Galois group can be endowed
with a Hopf algebra structure. These facts inspire the notion of Hopf-Galo
is extension: an extension that admits a Hopf algebra together with a line
ar action on the top field satisfying analogous conditions. Such a pair is
called a Hopf-Galois structure. Consequently\, every Galois extension is
Hopf-Galois\, but not the other way around. This is the beginning of Hopf-
Galois theory\, a generalization of Galois theory that was introduced in t
he sixties of the last century and have provided a useful setting to gener
alize notions and results from Galois theory. More recently\, it was found
that each Hopf-Galois structure on a Galois extension corresponds to a sk
ew brace: a set endowed with two group structures satisfying a variant of
the distributive property. The theory of skew braces was introduced in 200
7 and owes its interest to its applications on the study of the Yang-Baxte
r equation. This is how a connection between Hopf-Galois theory and skew b
races was established\, leading to a big body of research in the last year
s. In this talk\, we provide an introduction to both of these topics as we
ll as their link\, on which we shall view some recent results.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jack Thompson (The University of Western Australia)
DTSTART:20231018T110000Z
DTEND:20231018T120000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/15
DESCRIPTION:Title: Overdetermined problems involving the fractional Laplacian\nby J
ack Thompson (The University of Western Australia) as part of Barcelona Ma
thematics Informal Seminar (SIMBa)\n\nLecture held in UB FMI\, Room B2.\n\
nAbstract\nOverdetermined problems are a class of partial differential bou
ndary value problem where "too many" boundary conditions are imposed on th
e solution. Such problems appear in physics\, biology\, and other applied
sciences due to their strong connection with shape optimisation. The mathe
matical objective is to understand and classify the regions that admit sol
utions that satisfy all the required properties.\n\nA classical result in
this area is Serrin's problem\, which says that a bounded domain in $\\mat
hbb R^n$ that admits a function with constant Laplacian\, zero Dirichlet d
ata\, and constant Neumann data must be a ball. We will consider two gener
alisations of this problem\, both driven by the fractional Laplacian\, and
give an overview of the current literature and open problems.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eloi Torrents Juste (niversitat Autònomia de Barcelona)
DTSTART:20231108T120000Z
DTEND:20231108T130000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/16
DESCRIPTION:Title: Fundamental domains for the Bruhat-Tits tree for $GL_2(F_p)$\nby
Eloi Torrents Juste (niversitat Autònomia de Barcelona) as part of Barce
lona Mathematics Informal Seminar (SIMBa)\n\nLecture held in UAB\, Aula pe
tita CRM.\n\nAbstract\nThe computation of fundamental domains of the Bruha
t-Tits tree by the action of\nquaternionic groups allows the computation o
f harmonic cocycles on it. These are\nrelated to automorphic forms and fro
m this fact are derived several applications\, as\nfor example the computa
tion of points on Shimura curves and Heegner points on\nelliptic curves as
done by M. Greenberg and later generalized by C. Franc and M.\nMasdeu.\n\
nIn this talk we will review these concepts\, and we will explain how to a
pply them\nin the computation of Heegner points on elliptic curves in case
s where the Heegner\nhypothesis is not satisfied\, and therefore the class
ical arquimedian construction of\nthese points is difficult to compute.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Renzo Bruera Méndez (Universitat Politècnica de Catalunya)
DTSTART:20231129T120000Z
DTEND:20231129T130000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/17
DESCRIPTION:Title: An interior regularity result for the MEMS problem\nby Renzo Bru
era Méndez (Universitat Politècnica de Catalunya) as part of Barcelona M
athematics Informal Seminar (SIMBa)\n\nLecture held in UPC FME\, Aula 005.
\n\nAbstract\nIn this talk we present an interior regularity result for th
e class of stable solutions to a semilinear elliptic equation with a singu
lar nonlinearity. The class of nonlinearities that we consider are real-va
lued functions defined on [0\,1) which are positive\, nondecreasing\, and
whose integral on [0\,1) is infinite. This equation is a generalization of
a model for the deflection of a dielectric elastic membrane in a microele
ctromechanical system (MEMS).\n\nSolutions to this equation are critical p
oints of an associated energy functional. We say that a solution is stable
when the second variation of the energy at the solution is nonnegative. U
nder a growth assumption on the nonlinearity\, we are able to prove that e
very stable solution is regular up to the optimal dimension\, n=6.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Enric Solé Farré (Imperial College London - University College L
ondon)
DTSTART:20231220T100000Z
DTEND:20231220T110000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/18
DESCRIPTION:Title: Cohomogeneity one - From PDEs to groups and ODEs\nby Enric Solé
Farré (Imperial College London - University College London) as part of B
arcelona Mathematics Informal Seminar (SIMBa)\n\nLecture held in UB FMI\,
Aula B1.\n\nAbstract\nOne of the main problems in differential geometry is
solving PDEs involving different geometric quantities. Solutions to most
of these PDEs are hard to come by\, and one is often forced to reduce to v
ery symmetric scenarios to find examples of solutions. \n\nI will first re
vise some instances of the case with maximal symmetry: homogeneous space\;
before moving to the cohomogeneity one case. The driving PDE examples wil
l be the Einstein equation and the exceptional holonomy conditons.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Robin Simoens (Universitat Politècnica de Catalunya)
DTSTART:20240110T120000Z
DTEND:20240110T130000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/19
DESCRIPTION:Title: Coding theory: into the quantum world\nby Robin Simoens (Univers
itat Politècnica de Catalunya) as part of Barcelona Mathematics Informal
Seminar (SIMBa)\n\nLecture held in UPC FME\, Aula 005.\n\nAbstract\nClassi
cal error-correcting codes were introduced in 1950 by Richard Hamming and
are now well-developed. They are built upon the idea of adding redundant i
nformation to protect against errors. In 1995\, Peter Shor showed that thi
s idea can be carried into the quantum world\, giving rise to quantum erro
r-correcting codes\, which play a central role in the realisation of quant
um computers. In this talk\, I will give an introduction to both classical
and quantum codes\, pointing out their differences and similarities.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Irene Macías Tarrío (Universitat de Barcelona)
DTSTART:20240228T120000Z
DTEND:20240228T130000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/20
DESCRIPTION:Title: Moduli spaces of stable vector bundles\nby Irene Macías Tarrío
(Universitat de Barcelona) as part of Barcelona Mathematics Informal Semi
nar (SIMBa)\n\nLecture held in UB (aula B3).\n\nAbstract\nModuli spaces ar
e essential constructions that arise in connection with classification pro
blems. When dealing with vector bundles on a smooth algebraic variety X\,
the moduli space of stable vector bundles parametrizes isomorphic classes
of stable vector bundles. This talk will start with the definition and con
struction of this moduli space from the point of view of algebraic geometr
y. After this there will be an overview of the Brill-Noether Theory\, whic
h concerns the study of certain subvarieties of this moduli space in order
to know more about its geometry.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dídac Gil Rams (Centre de Recerca Matemàtica)
DTSTART:20240306T120000Z
DTEND:20240306T130000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/21
DESCRIPTION:Title: Splitting of separatrices in generalized standard maps\nby Dída
c Gil Rams (Centre de Recerca Matemàtica) as part of Barcelona Mathematic
s Informal Seminar (SIMBa)\n\nLecture held in UPC.\n\nAbstract\nWe study t
ransversal intersections between the invariant manifolds (stable and unsta
ble) associated to an hyperbolic fixed point for a class of maps. These in
tersections are known as homoclinic\norbits.\nThe existence of these kind
of orbits is one of the most celebrated methods to prove the existence of\
nchaotic dynamics in a system. Indeed the Morse-Smale theorem ensures that
if there exist transversal intersections between the invariant manifolds
of the same invariant object\, the system is locally conjugate to a Smale
horseshoe with infinite symbols.\n\nWe look for this phenomena in the name
d generalized standard maps. This generalization includes the already stud
ied maps like the standard map\, first studied by Lazutkin\, or the pertur
bed McMillan map.\nWe obtain an asymptotic formula for the Lazutkin invari
ant\, value related to the area between two homoclinic points\, and its fi
rst term depends on a Stokes constant that is generically different from z
ero. To do so\, one of the techniques that we use is the inner equation re
lated to our generalized standard maps.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Miquel Saucedo (Centre de Recerca matemàtica)
DTSTART:20240214T120000Z
DTEND:20240214T130000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/23
DESCRIPTION:Title: Subcritical uncertainty principles for the Fourier transform\nby
Miquel Saucedo (Centre de Recerca matemàtica) as part of Barcelona Mathe
matics Informal Seminar (SIMBa)\n\nLecture held in UAB (CRM aula petita).\
n\nAbstract\nIn this talk I will discuss a type of "relaxed" uncertainty p
rinciple for the Fourier transform which has applications in the study of
the Schrödinger equation. The main tools are polynomial approximation in
equalities.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alejandro García Sánchez (Universidad Autónoma de Barcelona)
DTSTART:20240320T120000Z
DTEND:20240320T130000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/24
DESCRIPTION:Title: Geometría y topología de espacios de Teichmüller\nby Alejandr
o García Sánchez (Universidad Autónoma de Barcelona) as part of Barcelo
na Mathematics Informal Seminar (SIMBa)\n\nLecture held in UAB (aula petit
a CRM).\n\nAbstract\nSe construyen los espacios de Teichmüller en el cont
exto del problema de clasificación de superficies de Riemann cerradas. En
primer lugar\, analizaremos el primer caso no trivial (género 1)\, que n
os permitirá dotar al espacio de móduli de una rica estructura geométri
ca vía un espacio que llamaremos de Teichmüller. A partir de ahí\, el o
bjetivo es mostrar la generalización para género superior de estos dos e
spacios y hacer énfasis en la "naturalidad" de estas construcciones\, si
bien se evita por completo el tratamiento del tema desde teoría de catego
rías.\n\nPizza for everyone after the talk!\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anna Jové (Universitat de Barcelona)
DTSTART:20240403T110000Z
DTEND:20240403T120000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/25
DESCRIPTION:Title: Pesin's theory in a transcendental setting\nby Anna Jové (Unive
rsitat de Barcelona) as part of Barcelona Mathematics Informal Seminar (SI
MBa)\n\nLecture held in FMI (UB): aula IA.\n\nAbstract\nRoughly speaking\,
Pesin's theory for R^n diffeomorphisms states that the asymptotical contr
action or expansion around almost-every orbit is controlled by the Lyapuno
v exponents (as long as none of them is zero). For rational maps\, this tr
anslates into well-defined generic inverse branches around almost-everywhe
re in the Julia set (Przytycki). In this talk\, I will explain the previou
s statements\, and I will discuss its possible generalizations to transcen
dental maps (Fagella-J.).\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/25/
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BEGIN:VEVENT
SUMMARY:Eva Philippe (Universitat de Barcelona and Sorbonne Université)
DTSTART:20240424T110000Z
DTEND:20240424T120000Z
DTSTAMP:20260404T110831Z
UID:SIMBa/26
DESCRIPTION:Title: Regular subdivisions and triangulations\nby Eva Philippe (Univer
sitat de Barcelona and Sorbonne Université) as part of Barcelona Mathemat
ics Informal Seminar (SIMBa)\n\nLecture held in FMI (UB): aula TBA.\n\nAbs
tract\nSubdivisions and triangulations of point configurations in R^d are
a central topic of polyhedral combinatorics and among them regular subdivi
sions form a particular family which enjoys special geometric properties.\
n\nA subdivision is regular if it can be obtained by taking the lower face
s of a lifting of its vertices in one dimension higher. This lifting proce
ss was central to improve the best known lower bound on the number of comb
inatorial types of polytopes (joint work with Arnau Padrol and Francisco S
antos).\nMoreover\, it happens that among the set of all subdivisions of a
fixed point configuration\, the regular ones have a particular topologica
l structure. Indeed\, they are in correspondence with the faces of a polyt
ope called the secondary polytope.\n
LOCATION:https://stable.researchseminars.org/talk/SIMBa/26/
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