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BEGIN:VEVENT
SUMMARY:Mirna Dzamonja (University of East Anglia / IHPST\, CNRS)
DTSTART:20200424T140000Z
DTEND:20200424T153000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/1
DESCRIPTION:Title: On wide Aronszajn trees\nby Mirna Dzamonja (
University of East Anglia / IHPST\, CNRS) as part of Bogotá logic seminar
\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Darío Alejandro García (Universidad de los Andes)
DTSTART:20200429T210000Z
DTEND:20200429T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/2
DESCRIPTION:Title: Pseudofinite structures: asymptotic classes\, di
mensions and ranks.\nby Darío Alejandro García (Universidad de los A
ndes) as part of Bogotá logic seminar\n\n\nAbstract\nThe fundamental theo
rem of ultraproducts ( Łoś’ Theorem) provides a transference principle
between the finite structures and their limits and provides an interestin
g duality between finite structures and their infinite ultraproducts. This
kind of finite/infinite connection can sometimes be used to prove qualita
tive properties of large finite structures using the powerful known method
s and results coming from infinite model theory\, and in the other directi
on\, quantitative properties in the finite structures often induce desirab
le model-theoretic properties in their ultraproducts. \nIn this talk I wil
l review some concepts on pseudofinite structures\, and present joint work
with D. Macpherson and C. Steinhorn (cf. [1]) where we explored condition
s on the (fine) pseudofinite dimension that guarantee good model-theoretic
properties (simplicity or supersimplicity\, and finite SU-rank) of the un
derlying theory of an ultraproduct of finite structures\, as well as a cha
racterization of forking in terms of decrease of the pseudofinite dimensio
n. The main examples of structures with these properties are ultraproducts
of asymptotic classes of finite structures (cf. [2])\, which are supersim
ple of finite SU-rank. If time permits\, I will also present recent joint
work with A. Berenstein and T. Zou that where we study some constructions
that naturally provide examples with infinite SU-rank.\n\n[1] Darío Garc
ía\, Dugald Macpherson\, Charles Steinhorn\, Pseudofinite structures and
simplicity\, Journal of Mathematical Logic\, vol.15 (2015)\, no. 01\, 1550
002 \n\n[2] Dugald Macpherson and Charles Steinhorn\, One-dimensional asym
ptotic classes of finite structures\, Transactions of the American Mathema
tical Society\, vol. 360 (2008)\, no. 1\, pp. 411–448.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Miguel Moreno (Kurt Gödel Research Center (KGRC) for Mathematical
Logic (Vienna))
DTSTART:20200508T140000Z
DTEND:20200508T153000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/3
DESCRIPTION:Title: Consistency of Filter Reflection\nby Miguel
Moreno (Kurt Gödel Research Center (KGRC) for Mathematical Logic (Vienna)
) as part of Bogotá logic seminar\n\n\nAbstract\nAbstract: Filter reflect
ion is an abstract version of stationary reflection. In this talk we will
give the definition of filter reflection and different avatars of it. We w
ill show that filter reflection is compatible with large cardinals\, forci
ng axioms\, also V=L. We will also discuss how to force filter reflection
and its applications to Generalized Descriptive Set Theory.\n\nThis is joi
nt work with Gabriel Fernandes and Assaf Rinot.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zaniar Ghadernezhad (Imperial College London)
DTSTART:20200522T140000Z
DTEND:20200522T153000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/5
DESCRIPTION:Title: Group topologies on automorphism groups of homog
eneous structures\nby Zaniar Ghadernezhad (Imperial College London) as
part of Bogotá logic seminar\n\n\nAbstract\nAbstract: Automorphism group
s of structures endowed with the topology generated by stabilisers of smal
l subsets are topological groups and indeed when countable they are Polish
. The interaction between the topological/dynamical properties of automorp
hism group of a structure and the logical and combinatorial properties of
the structure has been widely studied in recent years. In this talk I will
discuss different group topologies on automorphism groups of homogeneous
structures and especially focus on minimal group topologies. A Hausdorff t
opological group is called minimal if it does not admit a strictly coarser
Hausdorff group topology. I will provide some background\, and discuss se
veral classification of group topologies coarser than so called point-wise
convergence topology in the case of automorphism groups of countable homo
geneous structures and Urysohn space. This is a joint work with Javier de
la Nuez González.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carlos Di Prisco (IVIC / Universidad de los Andes)
DTSTART:20200527T210000Z
DTEND:20200527T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/6
DESCRIPTION:Title: Ideals and maximal almost disjoint families\
nby Carlos Di Prisco (IVIC / Universidad de los Andes) as part of Bogotá
logic seminar\n\n\nAbstract\nAbstract: We will present several results a
bout families of infinite sets of natural numbers that are almost disjoint
. In particular\, several recent results concerning the existence of def
inable maximal almost disjoint families. Almost disjoint families generate
ideals of sets that have interesting properties: the complement of such
an ideal is a selective coideal. We also present some results about select
ive and semiselective coideals and forcing notions related to them. In the
generic extension of the universe obtained by collapsing a Mahlo cardinal
to the first uncountable cardinal every definable set of real numbers is
H-Ramsey for every coideal H in a wide class of coideals.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rami Grossberg (Carnegie Mellon University)
DTSTART:20200603T210000Z
DTEND:20200603T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/7
DESCRIPTION:Title: On local & global questions in the theory of Abs
tract Elementary Classes\nby Rami Grossberg (Carnegie Mellon Universit
y) as part of Bogotá logic seminar\n\n\nAbstract\nAbstract: In the last 2
0 years (and more so in the last 10 years)\, Classification Theory for AEC
s (Abstract Elementary Classes) witnessed exponential growth\, with specta
cular results and also leading to a good theory generalizing first-order f
orking and various independence relations. The driving force was a combina
tion of global questions (like Shelah's categoricity conjecture) and a loc
al question about what properties of models in a fixed cardinality in a gi
ven AEC would imply existence of a model in its successor. I will describ
e some of the questions\, results and the interplay between them.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrés Villaveces (Universidad Nacional de Colombia - Bogotá)
DTSTART:20200610T210000Z
DTEND:20200610T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/8
DESCRIPTION:Title: On the interplay between Abstract Elementary Cla
sses and Categorical Logic\nby Andrés Villaveces (Universidad Naciona
l de Colombia - Bogotá) as part of Bogotá logic seminar\n\n\nAbstract\nA
bstract: I will describe two recent lines of interplay between Abstract El
ementary Classes and Categorical Logic: the problem of building the "Galoi
s group" of an AEC (building on Lascar and Poizat's work on the "Galois th
eory of model theory"\, and on the role of the Small Index Property - join
t work of mine with Ghadernezhad) and interpreting $\\lambda$-categoricity
in terms of properties of classifying topoi (recent work of Espíndola\,
connected to his ground-breaking work on Shelah's eventual categoricity co
njecture). My talk will stress the way these connections appear and the op
ening of new lines of possibility.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Paulo Soto (Universidad de los Andes)
DTSTART:20200617T210000Z
DTEND:20200617T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/9
DESCRIPTION:Title: Pseudofinitud y pseudocompacidad en lógica cont
inua\nby Paulo Soto (Universidad de los Andes) as part of Bogotá logi
c seminar\n\n\nAbstract\nLa noción de pseudofinitud en lógica de primer
orden ha probado ser una herramienta útil e interesante en las últimas d
écadas\, con aplicaciones importantes en combinatoria y teoría de grafos
. El propósito de la charla es definir el paralelo adecuado de la noción
de pseudofinitud en lógica continua\, explorar algunas nociones equivale
ntes y exponer un resultado sobre leyes 0-1 para los espacios métricos fi
nitos\, en respuesta parcial a la pregunta sobre la pseudofinitud de la es
fera de Urysohn.\n\n Ben Yaacov\, I. (2015). Fraïssé limits of metric
structures. J. Symb. Log.\, 80(1)\, 100–115.\n Goldbring\, I.\, & Ha
rt\, B. (2019). The almost sure theory of finite metric spaces arXiv: Logi
c.\n Goldbring\, I.\, & Lopes\, V. (2015). Pseudofinite and pseudocompa
ct metric structures Notre Dame J. Form. Log.\, 56(3)\, 493–510.\n Us
vyatsov\, A. (2008). Generic separable metric structures Topology Appl.\,
155(14)\, 1607–1617.\n\n(slides in English\, talk in Spanish)\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrés Felipe Uribe (Universidad Nacional de Colombia - Medellín
)
DTSTART:20200624T210000Z
DTEND:20200624T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/10
DESCRIPTION:Title: Un problema de independencia en topología gene
ral: la conjetura del espacio normal de Moore\, caso separable\nby And
rés Felipe Uribe (Universidad Nacional de Colombia - Medellín) as part o
f Bogotá logic seminar\n\n\nAbstract\nResumen: La conjetura del espacio
normal de Moore es un problema que se refiere a la metrización de espacio
s topológicos\, planteado por F. B. Jones en 1937 y que se convirtió en
uno de los problemas más importantes de la historia de la topología gene
ral. El propósito de la charla es explorar algunas relaciones entre teor
ía de conjuntos y la topología general\, presentando las implicaciones q
ue tienen tanto el Axioma de constructibilidad como el Axioma de Martin en
los espacios normales de Moore y establecer qué papel juegan en la indep
endencia del caso separable de la conjetura en cuestión.\n\nBibliografía
: \n\n-Jones\, F. B. (1937). Concerning normal and completely normal space
s. Bulletin American Mathematical Society 47\, p. 671-677.\n\n-Tall\, F.
D. (1969). Set-theoretic consistency results and topological theorems conc
erning the normal Moore space conjecture and related problem\, University
of Wisconsin\, Madison\, (PhD).\n\n-Parra-Londoño\, Carlos M. & Uribe-Zap
ata\, Andrés F. (2020). La independencia de una versión débil de la con
jetura del espacio normal de Moore. Rev. Integr. Temas Mat. 38\, Nr. 1\,
p. 43-54.\n\n(talk in Spanish\, slides in English)\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Boris Zilber (University of Oxford)
DTSTART:20200513T150000Z
DTEND:20200513T163000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/11
DESCRIPTION:Title: Syntax\, definability and geometry\nby Bori
s Zilber (University of Oxford) as part of Bogotá logic seminar\n\n\nAbst
ract\nAbstract: I will start by talking about syntax/semantics duality in
geometry and then explain some deep insights of Grothendieck in terms of m
odel theory.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Ignacio Agudelo (Universidad Nacional de Colombia - Bogotá)
DTSTART:20200701T210000Z
DTEND:20200701T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/12
DESCRIPTION:Title: On the space of stably dominated types of ACVF<
/a>\nby Juan Ignacio Agudelo (Universidad Nacional de Colombia - Bogotá)
as part of Bogotá logic seminar\n\n\nAbstract\nAbstract: I will describe
some model-theoretic ideas around the work of Hrushovski and Loeser on ACV
F\, with emphasis on the pro-definable structure and its connections to no
n-archimedean geometry.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Calderón (University of Toronto)
DTSTART:20200826T210000Z
DTEND:20200826T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/13
DESCRIPTION:Title: Nullity notions on the real line\nby Daniel
Calderón (University of Toronto) as part of Bogotá logic seminar\n\n\nA
bstract\nBorel conjecture asserts that all strong measure zero subsets of
the real line are countable. The interest of this problem is two-fold: in
one hand\, it gives a connection between abstract set theory and problems
in analysis and on the other hand the proof of its consistency\, due to La
ver\, contains the first use of countable support iterated forcing (this w
ill produce such deep developments as the Proper Forcing Axiom).\n\nStrong
measure zero subsets of the reals can be characterized in various ways: a
lgebraically (Galvin--Mycielski--Solovay)\, through selection principles\,
topological games\, and Ramsey-theoretic methods (Scheepers)\, and by the
mean of tools coming from geometric measure theory (Besicovitch and Zindu
lka). This motivates a systematic study of \\emph{nullity notions on the r
eal line}\; a hierarchy of subsets of the reals whose measure-theoretic na
ture lies in between being countable and being a Lebesgue-null set.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:John Baldwin (University of Illinois at Chicago)
DTSTART:20200902T210000Z
DTEND:20200902T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/14
DESCRIPTION:Title: On Strongly Minimal Steiner Systems: Zilber’s
Conjecture\, Universal Algebra\, and Combinatorics\nby John Baldwin (
University of Illinois at Chicago) as part of Bogotá logic seminar\n\n\nA
bstract\nThis talk deals with several issues.\n\n(1) The construction for
every $k$ of $2^{\\aleph_0}$ strongly minimal Steiner systems $2^{\\aleph_
0}$ where each line has length $k$ and are counterexamples to the Zilber t
richotomy.\n\n(2) The analysis of groups acting on ‘Hrushovski’ constr
uctions provides a detailed description of the algebraic closure of a fini
te set. This beginning of a Galois theory yields for both Hrushovski’s o
riginal constructions and Steiner systems as ternary relations:\n\n(a) fai
lure to admit elimination of imaginaries.\n\n(b) Restricting the $\\mu$-fu
nction implies there is no parameter free definable binary function.\n\n(3
) It is well-known that the existence of $k$-Steiner systems with cardinal
ity $n < \\omega$ is dependent on number theoretic properties of $k$ and $
n$. In contrast\, there are strongly minimal $k$-Steiner systems for every
$k$. And quasigroup structures can be imposed on these models if $k$ is a
prime power. Item 2b) shows this imposed structure can not be definable.\
n\n(4) Thus we see there are a wide variety of Hrushovski style strongly m
inimal sets. Specifying different theories of the finite structures\, the
particular specification of the $\\mu$ function\, etc. yield different alg
ebraic and combinatorial properties of the strongly minimal generic struct
ure.\n\n(a) There is a class of strongly minimal sets which are neither lo
cally modular nor trivial but $\\emptyset$-definable operations are ‘ess
entially unary’.\n\n(b) Another class contains strongly minimal quasigro
ups which induce Steiner systems with prime power line length. The associa
ted varieties (universal algebra) are permutable\, congruence regular\, an
d congruence uniform\, but not locally finite.\n\n(c) This observation lea
ds to a new perspective on the ample hierarchy.\n\n(5) Extending the notio
n of an $(a\, b)$-cycle graph arising in the study of finite and infinite
Stein triple systems ([CW12]) we introduce the $(a\, b)$-path graph of a b
lock algebra. We exhibit theories of strongly minimal block algebras where
all $(a\, b)$-paths are infinite and others in which all are finite only
in the prime model. This involves joint work with Gianlucca Paolini [BP20]
and Viktor Verbovskiy [BV20] and [Bal20]. Items 2) and 3) require the sep
arate analysis of the subgroups of $aut(M)$ (the generic model of $T_\\mu$
with respect to the subgroup of automorphisms $G_I$ (fixing $I$ pointwise
) and $G_{\\{ I\\}}$ (fixing $I$ setwise).\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matteo Viale (Università di Torino)
DTSTART:20200911T140000Z
DTEND:20200911T153000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/15
DESCRIPTION:Title: Tameness for set theory\nby Matteo Viale (U
niversità di Torino) as part of Bogotá logic seminar\n\n\nAbstract\nWe s
how that (assuming large cardinals) set theory is a tractable (and we dare
to say tame) first order theory when formalized in a first order signatur
e with natural predicate symbols for the basic definable concepts of secon
d and third order arithmetic\, and appealing to the model-theoretic notion
s of model completeness and model companionship.\n\nSpecifically we develo
p a general framework linking generic absoluteness results to model compan
ionship and show that (with the required care in details) a -property form
alized in an appropriate language for second or third order number theory
is forcible from some T extending ZFC + large cardinals if and only if it
is consistent with the universal fragment of T if and only if it is realiz
ed in the model companion of T.\n\nPart (but not all) of our results are c
onditional to the proof of Schindler and Asperò that Woodin’s axiom (*)
can be forced by a stationary set preserving forcing.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:André Platzer (Carnegie Mellon University)
DTSTART:20200923T210000Z
DTEND:20200923T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/16
DESCRIPTION:Title: Logical Foundations of Cyber-Physical Systems\nby André Platzer (Carnegie Mellon University) as part of Bogotá logi
c seminar\n\n\nAbstract\nLogical foundations of cyber-physical systems (CP
S) study systems that combine cyber aspects such as communication and comp
uter control with physical aspects such as movement in space. CPS applicat
ions abound. Ensuring their correct functioning\, however\, is a serious
challenge. Scientists and engineers need analytic tools to understand and
predict the behavior of their systems. That's the key to designing smart
and reliable control.\n\nThis talk identifies a mathematical model for CP
S called multi-dynamical systems\, i.e. systems characterized by combining
multiple facets of dynamical systems\, including discrete and continuous
dynamics\, but also uncertainty resolved by nondeterministic\, stochastic\
, and adversarial dynamics. Multi-dynamical systems help us understand CP
Ss better\, as being composed of multiple dynamical aspects\, each of whic
h is simpler than the full system. The family of differential dynamic log
ics surveyed in this talk exploits this compositionality in order to tame
the complexity of CPS and enable their analysis.\n\nIn addition to providi
ng a strong theoretical foundation for CPS\, differential dynamic logics h
ave also been instrumental in verifying many applications\, including the
Airborne Collision Avoidance System ACAS X\, the European Train Control Sy
stem ETCS\, several automotive systems\, mobile robot navigation with the
dynamic window algorithm\, and a surgical robotic system for skull-base su
rgery. The approach is implemented in the theorem prover KeYmaera X.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Artem Chernikov (University of California at Los Angeles)
DTSTART:20200916T210000Z
DTEND:20200916T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/17
DESCRIPTION:Title: Incidence counting and trichotomy in o-minimal
structures\nby Artem Chernikov (University of California at Los Angele
s) as part of Bogotá logic seminar\n\n\nAbstract\nZarankiewicz’s proble
m in graph theory asks to determine the largest possible number of edges $
|E|$ in a bipartite graph $G = (E\, V_1\, V_2)$ with the parts $V_1$ and $
V_2$ containing $m$ and $n$ vertices\, respectively\, and such that $G$ co
ntains no complete bipartite subgraphs on $k$ vertices. Graphs definable i
n o-minimal (or more generally distal structures) enjoy stronger bounds th
an general graphs\, providing an abstract setting for the Szemerédi-Trott
er theorem and related incidence bounds. We obtain almost optimal upper an
d lower bounds for hypergraphs definable in locally modular o-minimal stru
ctures\, along with some applications to incidence counting (e.g. the numb
er of incidences between points and boxes with axis parallel sides on the
plane whose incidence graph is $K_{k\,k}$-free is almost linear). We expla
in how the exponent appearing in these bounds is tightly connected to the
trichotomy principle in o-minimal structures.\n\nJoint work with Abdul Bas
it\, Sergei Starchenko\, Terence Tao and Chieu-Minh Tran.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Silvia Barbina (The Open University)
DTSTART:20201016T140000Z
DTEND:20201016T153000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/18
DESCRIPTION:Title: The theory of the universal-homogeneous Steiner
triple system\nby Silvia Barbina (The Open University) as part of Bog
otá logic seminar\n\n\nAbstract\nA Steiner triple system is a set $S$ tog
ether with a collection $B$ of subsets of $S$ of size $3$ such that any tw
o elements of $S$ belong to exactly one element of $B$. It is well known t
hat the class of finite Steiner triple systems has a Fraïssé limit\, the
countable homogeneous universal Steiner triple system $M$. In joint work
with Enrique Casanovas\, we have proved that the theory $T$ of $M$ has qua
ntifier elimination\, is not small\, has $TP_2$\, $NSOP_1$\, eliminates hy
perimaginaries and weakly eliminates imaginaries. In this talk I will revi
ew the construction of $M$\, give an axiomatisation of $T$ and prove some
of its properties.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:John Goodrick (Universidad de los Andes)
DTSTART:20200930T210000Z
DTEND:20200930T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/19
DESCRIPTION:by John Goodrick (Universidad de los Andes) as part of Bogotá
logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Amador Martín Pizarro (Universität Freiburg)
DTSTART:20201023T140000Z
DTEND:20201023T153000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/20
DESCRIPTION:Title: Arithmetic progressions and complete amalgamati
on\nby Amador Martín Pizarro (Universität Freiburg) as part of Bogot
á logic seminar\n\n\nAbstract\nHindman’s theorem states that\, given a
finite colouring of the natural numbers\, there is an infinite monochromat
ic set such that all the finite sums of its elements enumerated in increas
ing order have again the same color. In particular\, there is a monochrom
atic triangle $(x\,y\, x+y)$. A related question is Roth’s theorem on ar
ithmetic progression\, which asks whether a subset $A$ of the natural numb
ers of positive (upper) density contains an arithmetic progression of leng
th 3\, that is\, a tuple $(a\, a+b\, a+2b)$ in $A\\times A\\times A$. Fini
tary versions of Roth’s theorem study subsets $A$ of $\\{0\,\\ldots\, N\
\}$ whose density is greater than a fixed lower bound\, and ask whether th
e same holds for sufficiently large $N$. \n\nWe will report on recent work
with Daniel Palacín on how to prove Roth’s theorem in the context of p
seudo-finite groups with the associated counting measure\, using technique
s from geometric model theory\, and particularly\, (a version of) complete
amalgamation problems\, resonating with the independence theorem in simpl
e theories. In this talk\, we will not discuss the technical aspects of th
e proof\, but present the main ideas to a general audience with a familiar
ity in mathematical logic.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alf Onshuus (Universidad de los Andes)
DTSTART:20201028T210000Z
DTEND:20201028T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/21
DESCRIPTION:Title: Omega categorical dependent structures of ordin
al th-rank\nby Alf Onshuus (Universidad de los Andes) as part of Bogot
á logic seminar\n\n\nAbstract\nClassification problems in model theory (u
nderstanding and characterizing all theories in a fixed language that have
certain properties) are a recurrent theme that has only been solved under
very particular assumptions. Totally categorical structures can be classi
fied by results of Lachlan and Hrushovski. Certain classes of pseudofinite
structures were classified by Cherlin and Hrushovski in the book "Finite
Structures with Few Types".\n\n\nIn this talk we will give a sketch of how
these classifications were achieved and talk about the classification pro
blem for omega categorical dependent super rosy theories. Some results we
will talk about include:\n\n Characterization of omega categorical th-r
ank one dependent structures.\n\n Coordinatization for omega categorica
l dependent omega categorical structures of finite th-rank.\n\n Every o
mega categorical dependent super rosy structure has finite th-rank.\n\nA c
orollary of these results is that for any fixed countable language\, there
are only countably many finitely homogeneous relational super rosy depend
ent theories (modulo isomorphism).\n\n\nAll results are joint work with Pi
erre Simon. I will give definitions and intuitions for all the terms menti
oned above.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Samson Abramsky (University of Oxford)
DTSTART:20201106T140000Z
DTEND:20201106T153000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/22
DESCRIPTION:Title: The logic of contextuality\nby Samson Abram
sky (University of Oxford) as part of Bogotá logic seminar\n\n\nAbstract\
n(joint work with Rui Soares Barbosa): Contextuality is a key signature of
quantum non-classicality\, which has been shown to play a central role in
enabling quantum advantage for a wide range of information-processing and
computational tasks.\n\nWe study the logic of contextuality from a struct
ural point of view\, in the setting of partial Boolean algebras introduced
by Kochen and Specker in their seminal work.\n\nThese contrast with tradi
tional quantum logic a la Birkhoff--von Neumann in that operations such as
conjunction and disjunction are partial\, only being defined in the domai
n where they are physically meaningful.\n\nWe study how this setting relat
es to current work on contextuality such as the sheaf-theoretic and graph-
theoretic approaches.\n\nWe introduce a general free construction extendin
g the commeasurability relation on a partial Boolean algebra\, i.e. the do
main of definition of the binary logical operations.\n\nThis construction
has a surprisingly broad range of uses.\n\nWe apply it in the study of a n
umber of issues\, including:\n\n- establishing the connection between the
abstract measurement scenarios studied in the contextuality literature and
the setting of partial Boolean algebras\;\n\n- formulating various contex
tuality properties in this setting\, including probabilistic contextuality
as well as the strong\, state-independent notion of contextuality given b
y Kochen--Specker paradoxes\, which are logically contradictory statements
validated by partial Boolean algebras\, specifically those arising from q
uantum mechanics\;\n\n- investigating a Logical Exclusivity Principle\, an
d its relation to the Probabilistic Exclusivity Principle widely studied i
n recent work on contextuality as a step towards closing in on the set of
quantum-realisable correlations\;\n\n- developing some work towards a logi
cal characterisation of the Hilbert space tensor product\, using logical e
xclusivity to capture some of its salient quantum features.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sasha Post (Universidad de los Andes)
DTSTART:20201111T210000Z
DTEND:20201111T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/23
DESCRIPTION:Title: Lie groups and definability\nby Sasha Post
(Universidad de los Andes) as part of Bogotá logic seminar\n\n\nAbstract\
nIt is well known (Pillay\, 1980) that a group G definable in an o-minimal
expansion of the reals can be equipped with a Lie group structure\; that
is a topology making G a smooth variety such that the multiplication and i
nverse maps are smooth. It is then natural to ask whether the contrary is
true\, that is if any Lie group is actually definable in an o-minimal expa
nsion of ℝ . We cannot expect this to be true in full generality since d
efinable groups must have finitely many connected components but we still
get some nice results for connected Lie groups. In 2016 A. Conversano\, A.
Onshuus and S. Starchenko gave a criterion for solvable Lie groups. After
setting the general frame of work we will recall this solvable criterion.
We will continue with a criterion for the case when the group is linear a
nd we will also deal with non linear Lie groups that have “nice Levi dec
omposition”. If time allows it we will give a few words about recent wor
k on the general case.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Berenstein (Universidad de los Andes)
DTSTART:20201118T210000Z
DTEND:20201118T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/24
DESCRIPTION:by Alexander Berenstein (Universidad de los Andes) as part of
Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rosario Mennuni (Universität Münster)
DTSTART:20201125T210000Z
DTEND:20201125T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/25
DESCRIPTION:Title: The domination monoid\nby Rosario Mennuni (
Universität Münster) as part of Bogotá logic seminar\n\n\nAbstract\nThi
s talk is concerned with the interaction between the semigroup of invarian
t types and the preorder of domination\, i.e. small-type semi-isolation.
In the superstable case\, the induced quotient semigroup\, which goes unde
r the name of "domination monoid"\, parameterises "finitely generated satu
rated extensions of U" and how they can be amalgamated independently. In g
eneral\, the situation is much wilder\, and the domination monoid need not
even be well-defined. \n\nNevertheless\, this object has been used to for
mulate AKE-type results\, can be computed in various natural examples\, an
d there is heuristic evidence that well-definedness may hold under NIP. I
will give an overview of the subject and present some results on these obj
ects from my thesis.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sylvy Anscombe (University of Central Lancashire & Imperial Colleg
e)
DTSTART:20201202T210000Z
DTEND:20201202T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/26
DESCRIPTION:by Sylvy Anscombe (University of Central Lancashire & Imperial
College) as part of Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Valderrama (Universidad Nacional de Colombia)
DTSTART:20201209T210000Z
DTEND:20201209T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/27
DESCRIPTION:by David Valderrama (Universidad Nacional de Colombia) as part
of Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marcos Mazari-Armida (Carnegie Mellon University)
DTSTART:20210127T210000Z
DTEND:20210127T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/28
DESCRIPTION:Title: Characterizing noetherian rings via superstabil
ity\nby Marcos Mazari-Armida (Carnegie Mellon University) as part of B
ogotá logic seminar\n\n\nAbstract\nWe will show how superstability of cer
tain classes of modules can be used to characterize noetherian rings. None
of the classes of modules that we will consider are axiomatizable by a co
mplete first-order theory and some of them are not even first-order axioma
tizable\, but they are all Abstract Elementary Classes. This new way of lo
oking at classes of modules as AECs will be emphasized as I think it can h
ave interesting applications. If time permits we will see how the ideas pr
esented can be used to characterize other classical rings.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Javier de la Nuez González (Universidad del País Vasco)
DTSTART:20210212T140000Z
DTEND:20210212T153000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/29
DESCRIPTION:Title: Some model theory of the curve graph\nby Ja
vier de la Nuez González (Universidad del País Vasco) as part of Bogotá
logic seminar\n\n\nAbstract\nThe curve graph of a surface of finite type
is a fundamental object in the study of its mapping class group both from
the metric and the combinatorial point of view. I will discuss joint work
with Valentina Disarlo and Thomas Koberda where we conduct a thorough stud
y of curve graphs from the model theoretic point of view\, with particular
emphasis in the problem of interpretability between different curve graph
s and other geometric complexes.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:H Jerome Keisler (University of Wisconsin-Madison)
DTSTART:20210224T210000Z
DTEND:20210224T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/30
DESCRIPTION:Title: Using Ultraproducts to Compare Continuous Struc
tures\nby H Jerome Keisler (University of Wisconsin-Madison) as part o
f Bogotá logic seminar\n\n\nAbstract\nWe revisit two research programs th
at were proposed in the 1960’s\, remained largely dormant for five decad
es\, and then become hot areas of research in the last decade.\n\nThe mono
graph “Continuous Model Theory” by Chang and Keisler\, Annals of Mathe
matics Studies (1966)\, studied structures with truth values in $[0\,1]$\,
with formulas that had continuous functions as connectives\, sup and inf
as quantifiers\, and equality. In 2008\, Ben Yaacov\, Bernstein\, Henson\,
and Usvyatsev introduced the model theory of metric structures\, where eq
uality is replaced by a metric\, and all functions and predicates are requ
ired to be uniformly continuous. This has led to an explosion of research
with results that closely parallel first order model theory\, with many ap
plications to analysis. In my forthcoming paper “Model Theory for Real-v
alued Structures”\, the ”Expansion Theorem” allows one to extend man
y model-theoretic results about metric structures to general $[0\,1]$-valu
ed structures–the structures in the 1966 monograph but without equality.
\n\nMy paper “Ultrapowers Which are Not Saturated”\, J. Symbolic Logic
32 (1967)\, 23-46\, introduced a pre-ordering $M \\trianglelefteq N$ on a
ll first-order structures\, that holds if every regular ultrafilter that s
aturates $N$ saturates $M$\, and suggested using it to classify structures
. In the last decade\, in a remarkable series of papers\, Malliaris and Sh
elah showed that that pre-ordering gives a rich classification of simple f
irst-order structures. Here\, we lay the ground-work for using the analogo
us pre-ordering to classify $[0\,1]$-valued and metric structures.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Caroline Terry (https://math.osu.edu/people/terry.376)
DTSTART:20210203T210000Z
DTEND:20210203T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/31
DESCRIPTION:Title: Speeds of hereditary properties and mutual alge
bricity\nby Caroline Terry (https://math.osu.edu/people/terry.376) as
part of Bogotá logic seminar\n\n\nAbstract\nA hereditary graph property i
s a class of finite graphs closed under isomorphism and induced subgraphs.
Given a hereditary graph property $H$\, the speed of $H$ is the function
which sends an integer $n$ to the number of distinct elements in H with un
derlying set $\\{ 1\,...\,n\\}$. Not just any function can occur as the sp
eed of hereditary graph property. Specifically\, there are discrete ``jump
s" in the possible speeds. Study of these jumps began with work of Scheine
rman and Zito in the 90's\, and culminated in a series of papers from the
2000's by Balogh\, Bollobás\, and Weinreich\, in which essentially all po
ssible speeds of a hereditary graph property were characterized. In contra
st to this\, many aspects of this problem in the hypergraph setting remain
ed unknown. In this talk we present new hypergraph analogues of many of th
e jumps from the graph setting\, specifically those involving the polynomi
al\, exponential\, and factorial speeds. The jumps in the factorial range
turned out to have surprising connections to the model theoretic notion of
mutual algebricity\, which we also discuss. This is joint work with Chris
Laskowski.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Scanlon (University of California - Berkeley)
DTSTART:20210217T210000Z
DTEND:20210217T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/32
DESCRIPTION:by Thomas Scanlon (University of California - Berkeley) as par
t of Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joel Nagloo (City University of New York)
DTSTART:20210303T210000Z
DTEND:20210303T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/33
DESCRIPTION:Title: Geometric triviality in differentially closed f
ields\nby Joel Nagloo (City University of New York) as part of Bogotá
logic seminar\n\n\nAbstract\nIn this talk we revisit the problem of descr
ibing the 'finer' structure of geometrically trivial strongly minimal sets
in $DCF_0$. In particular\, I will explain how recent work joint with Guy
Casale and James Freitag on Fuchsian groups (discrete subgroup of $SL_2(
\\mathbb{R})$) and automorphic functions\, has lead to intriguing question
s around the $\\omega$-categoricity conjecture of Daniel Lascar. This conj
ecture was disproved in its full generality by James Freitag and Tom Scanl
on using the modular group $SL_2(\\mathbb{Z})$ and its automorphic uniform
izer (the $j$-function). I will explain how their counter-example fits int
o the larger context of arithmetic Fuchsian groups and has allowed us to '
propose' refinements to the original conjecture.\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alex Kruckman (Wesleyan University)
DTSTART:20210310T210000Z
DTEND:20210310T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/34
DESCRIPTION:by Alex Kruckman (Wesleyan University) as part of Bogotá logi
c seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Menachem Magidor (Hebrew University of Jerusalem)
DTSTART:20210423T140000Z
DTEND:20210423T153000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/35
DESCRIPTION:by Menachem Magidor (Hebrew University of Jerusalem) as part o
f Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Felipe Carmona (Universidad Nacional de Colombia)
DTSTART:20210428T210000Z
DTEND:20210428T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/36
DESCRIPTION:by Juan Felipe Carmona (Universidad Nacional de Colombia) as p
art of Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Julián Cano (Universidad Nacional de Colombia)
DTSTART:20210505T210000Z
DTEND:20210505T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/37
DESCRIPTION:by Julián Cano (Universidad Nacional de Colombia) as part of
Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Samaria Montenegro (Universidad de Costa Rica)
DTSTART:20210512T210000Z
DTEND:20210512T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/38
DESCRIPTION:by Samaria Montenegro (Universidad de Costa Rica) as part of B
ogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Laura Gamboa (Universidad de los Andes)
DTSTART:20210519T210000Z
DTEND:20210519T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/39
DESCRIPTION:by Laura Gamboa (Universidad de los Andes) as part of Bogotá
logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juliette Kennedy (University of Helsinki)
DTSTART:20210528T140000Z
DTEND:20210528T153000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/40
DESCRIPTION:by Juliette Kennedy (University of Helsinki) as part of Bogot
á logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Isabel Müller (Imperial College - London)
DTSTART:20210609T210000Z
DTEND:20210609T223000Z
DTSTAMP:20260404T095039Z
UID:SeminarioFlotanteLogMatBog/41
DESCRIPTION:by Isabel Müller (Imperial College - London) as part of Bogot
á logic seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/SeminarioFlotanteLogMatB
og/41/
END:VEVENT
END:VCALENDAR