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BEGIN:VEVENT
SUMMARY:Mirna Dzamonja (University of East Anglia / IHPST\, CNRS)
DTSTART:20200424T140000Z
DTEND:20200424T153000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/1
DESCRIPTION:Title: On wide Aronszajn trees\nby Mirna Dzamonja (Univers
ity of East Anglia / IHPST\, CNRS) as part of Bogotá logic seminar\n\nAbs
tract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Darío Alejandro García (Universidad de los Andes)
DTSTART:20200429T210000Z
DTEND:20200429T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/2
DESCRIPTION:Title: Pseudofinite structures: asymptotic classes\, dimension
s and ranks.\nby Darío Alejandro García (Universidad de los Andes) a
s part of Bogotá logic seminar\n\n\nAbstract\nThe fundamental theorem of
ultraproducts ( Łoś’ Theorem) provides a transference principle betwee
n the finite structures and their limits and provides an interesting duali
ty between finite structures and their infinite ultraproducts. This kind o
f finite/infinite connection can sometimes be used to prove qualitative pr
operties of large finite structures using the powerful known methods and r
esults coming from infinite model theory\, and in the other direction\, qu
antitative properties in the finite structures often induce desirable mode
l-theoretic properties in their ultraproducts. \nIn this talk I will revie
w some concepts on pseudofinite structures\, and present joint work with D
. Macpherson and C. Steinhorn (cf. [1]) where we explored conditions on th
e (fine) pseudofinite dimension that guarantee good model-theoretic proper
ties (simplicity or supersimplicity\, and finite SU-rank) of the underlyin
g theory of an ultraproduct of finite structures\, as well as a characteri
zation of forking in terms of decrease of the pseudofinite dimension. The
main examples of structures with these properties are ultraproducts of asy
mptotic classes of finite structures (cf. [2])\, which are supersimple of
finite SU-rank. If time permits\, I will also present recent joint work wi
th A. Berenstein and T. Zou that where we study some constructions that na
turally provide examples with infinite SU-rank.\n\n[1] Darío García\, Du
gald Macpherson\, Charles Steinhorn\, Pseudofinite structures and simplici
ty\, Journal of Mathematical Logic\, vol.15 (2015)\, no. 01\, 1550002 \n\n
[2] Dugald Macpherson and Charles Steinhorn\, One-dimensional asymptotic c
lasses of finite structures\, Transactions of the American Mathematical So
ciety\, vol. 360 (2008)\, no. 1\, pp. 411–448.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Miguel Moreno (Kurt Gödel Research Center (KGRC) for Mathematical
Logic (Vienna))
DTSTART:20200508T140000Z
DTEND:20200508T153000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/3
DESCRIPTION:Title: Consistency of Filter Reflection\nby Miguel Moreno
(Kurt Gödel Research Center (KGRC) for Mathematical Logic (Vienna)) as pa
rt of Bogotá logic seminar\n\n\nAbstract\nAbstract: Filter reflection is
an abstract version of stationary reflection. In this talk we will give th
e definition of filter reflection and different avatars of it. We will sho
w that filter reflection is compatible with large cardinals\, forcing axio
ms\, also V=L. We will also discuss how to force filter reflection and its
applications to Generalized Descriptive Set Theory.\n\nThis is joint work
with Gabriel Fernandes and Assaf Rinot.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zaniar Ghadernezhad (Imperial College London)
DTSTART:20200522T140000Z
DTEND:20200522T153000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/5
DESCRIPTION:Title: Group topologies on automorphism groups of homogeneous
structures\nby Zaniar Ghadernezhad (Imperial College London) as part o
f Bogotá logic seminar\n\n\nAbstract\nAbstract: Automorphism groups of st
ructures endowed with the topology generated by stabilisers of small subse
ts are topological groups and indeed when countable they are Polish. The i
nteraction between the topological/dynamical properties of automorphism gr
oup of a structure and the logical and combinatorial properties of the str
ucture has been widely studied in recent years. In this talk I will discus
s different group topologies on automorphism groups of homogeneous structu
res and especially focus on minimal group topologies. A Hausdorff topologi
cal group is called minimal if it does not admit a strictly coarser Hausdo
rff group topology. I will provide some background\, and discuss several c
lassification of group topologies coarser than so called point-wise conver
gence topology in the case of automorphism groups of countable homogeneous
structures and Urysohn space. This is a joint work with Javier de la Nuez
González.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carlos Di Prisco (IVIC / Universidad de los Andes)
DTSTART:20200527T210000Z
DTEND:20200527T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/6
DESCRIPTION:Title: Ideals and maximal almost disjoint families\nby Car
los Di Prisco (IVIC / Universidad de los Andes) as part of Bogotá logic s
eminar\n\n\nAbstract\nAbstract: We will present several results about fa
milies of infinite sets of natural numbers that are almost disjoint. In p
articular\, several recent results concerning the existence of definable
maximal almost disjoint families. Almost disjoint families generate ideals
of sets that have interesting properties: the complement of such an idea
l is a selective coideal. We also present some results about selective and
semiselective coideals and forcing notions related to them. In the generi
c extension of the universe obtained by collapsing a Mahlo cardinal to the
first uncountable cardinal every definable set of real numbers is H-Rams
ey for every coideal H in a wide class of coideals.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rami Grossberg (Carnegie Mellon University)
DTSTART:20200603T210000Z
DTEND:20200603T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/7
DESCRIPTION:Title: On local & global questions in the theory of Abstract E
lementary Classes\nby Rami Grossberg (Carnegie Mellon University) as p
art of Bogotá logic seminar\n\n\nAbstract\nAbstract: In the last 20 years
(and more so in the last 10 years)\, Classification Theory for AECs (Abst
ract Elementary Classes) witnessed exponential growth\, with spectacular r
esults and also leading to a good theory generalizing first-order forking
and various independence relations. The driving force was a combination of
global questions (like Shelah's categoricity conjecture) and a local ques
tion about what properties of models in a fixed cardinality in a given AEC
would imply existence of a model in its successor. I will describe some
of the questions\, results and the interplay between them.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrés Villaveces (Universidad Nacional de Colombia - Bogotá)
DTSTART:20200610T210000Z
DTEND:20200610T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/8
DESCRIPTION:Title: On the interplay between Abstract Elementary Classes an
d Categorical Logic\nby Andrés Villaveces (Universidad Nacional de Co
lombia - Bogotá) as part of Bogotá logic seminar\n\n\nAbstract\nAbstract
: I will describe two recent lines of interplay between Abstract Elementar
y Classes and Categorical Logic: the problem of building the "Galois group
" of an AEC (building on Lascar and Poizat's work on the "Galois theory of
model theory"\, and on the role of the Small Index Property - joint work
of mine with Ghadernezhad) and interpreting $\\lambda$-categoricity in ter
ms of properties of classifying topoi (recent work of Espíndola\, connect
ed to his ground-breaking work on Shelah's eventual categoricity conjectur
e). My talk will stress the way these connections appear and the opening o
f new lines of possibility.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Paulo Soto (Universidad de los Andes)
DTSTART:20200617T210000Z
DTEND:20200617T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/9
DESCRIPTION:Title: Pseudofinitud y pseudocompacidad en lógica continua\nby Paulo Soto (Universidad de los Andes) as part of Bogotá logic semin
ar\n\n\nAbstract\nLa noción de pseudofinitud en lógica de primer orden h
a probado ser una herramienta útil e interesante en las últimas décadas
\, con aplicaciones importantes en combinatoria y teoría de grafos. El pr
opósito de la charla es definir el paralelo adecuado de la noción de pse
udofinitud en lógica continua\, explorar algunas nociones equivalentes y
exponer un resultado sobre leyes 0-1 para los espacios métricos finitos\,
en respuesta parcial a la pregunta sobre la pseudofinitud de la esfera de
Urysohn.\n\n Ben Yaacov\, I. (2015). Fraïssé limits of metric struct
ures. J. Symb. Log.\, 80(1)\, 100–115.\n Goldbring\, I.\, & Hart\, B.
(2019). The almost sure theory of finite metric spaces arXiv: Logic.\n
Goldbring\, I.\, & Lopes\, V. (2015). Pseudofinite and pseudocompact metr
ic structures Notre Dame J. Form. Log.\, 56(3)\, 493–510.\n Usvyatsov
\, A. (2008). Generic separable metric structures Topology Appl.\, 155(14)
\, 1607–1617.\n\n(slides in English\, talk in Spanish)\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrés Felipe Uribe (Universidad Nacional de Colombia - Medellín
)
DTSTART:20200624T210000Z
DTEND:20200624T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/10
DESCRIPTION:Title: Un problema de independencia en topología general: la
conjetura del espacio normal de Moore\, caso separable\nby Andrés Fe
lipe Uribe (Universidad Nacional de Colombia - Medellín) as part of Bogot
á logic seminar\n\n\nAbstract\nResumen: La conjetura del espacio normal
de Moore es un problema que se refiere a la metrización de espacios topol
ógicos\, planteado por F. B. Jones en 1937 y que se convirtió en uno de
los problemas más importantes de la historia de la topología general. El
propósito de la charla es explorar algunas relaciones entre teoría de c
onjuntos y la topología general\, presentando las implicaciones que tiene
n tanto el Axioma de constructibilidad como el Axioma de Martin en los esp
acios normales de Moore y establecer qué papel juegan en la independencia
del caso separable de la conjetura en cuestión.\n\nBibliografía: \n\n-J
ones\, F. B. (1937). Concerning normal and completely normal spaces. Bull
etin American Mathematical Society 47\, p. 671-677.\n\n-Tall\, F. D. (1969
). Set-theoretic consistency results and topological theorems concerning t
he normal Moore space conjecture and related problem\, University of Wisco
nsin\, Madison\, (PhD).\n\n-Parra-Londoño\, Carlos M. & Uribe-Zapata\, An
drés F. (2020). La independencia de una versión débil de la conjetura d
el 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://researchseminars.org/talk/SeminarioFlotanteLogMatBog/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Boris Zilber (University of Oxford)
DTSTART:20200513T150000Z
DTEND:20200513T163000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/11
DESCRIPTION:Title: Syntax\, definability and geometry\nby Boris Zilbe
r (University of Oxford) as part of Bogotá logic seminar\n\n\nAbstract\nA
bstract: I will start by talking about syntax/semantics duality in geometr
y and then explain some deep insights of Grothendieck in terms of model th
eory.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Ignacio Agudelo (Universidad Nacional de Colombia - Bogotá)
DTSTART:20200701T210000Z
DTEND:20200701T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/12
DESCRIPTION:Title: On the space of stably dominated types of ACVF\nby
Juan Ignacio Agudelo (Universidad Nacional de Colombia - Bogotá) as part
of Bogotá logic seminar\n\n\nAbstract\nAbstract: I will describe some mo
del-theoretic ideas around the work of Hrushovski and Loeser on ACVF\, wit
h emphasis on the pro-definable structure and its connections to non-archi
medean geometry.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Calderón (University of Toronto)
DTSTART:20200826T210000Z
DTEND:20200826T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/13
DESCRIPTION:Title: Nullity notions on the real line\nby Daniel Calder
ón (University of Toronto) as part of Bogotá logic seminar\n\n\nAbstract
\nBorel conjecture asserts that all strong measure zero subsets of the rea
l line are countable. The interest of this problem is two-fold: in one han
d\, it gives a connection between abstract set theory and problems in anal
ysis and on the other hand the proof of its consistency\, due to Laver\, c
ontains the first use of countable support iterated forcing (this will pro
duce such deep developments as the Proper Forcing Axiom).\n\nStrong measur
e zero subsets of the reals can be characterized in various ways: algebrai
cally (Galvin--Mycielski--Solovay)\, through selection principles\, topolo
gical games\, and Ramsey-theoretic methods (Scheepers)\, and by the mean o
f tools coming from geometric measure theory (Besicovitch and Zindulka). T
his motivates a systematic study of \\emph{nullity notions on the real lin
e}\; a hierarchy of subsets of the reals whose measure-theoretic nature li
es in between being countable and being a Lebesgue-null set.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:John Baldwin (University of Illinois at Chicago)
DTSTART:20200902T210000Z
DTEND:20200902T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/14
DESCRIPTION:Title: On Strongly Minimal Steiner Systems: Zilber’s Conjec
ture\, Universal Algebra\, and Combinatorics\nby John Baldwin (Univers
ity of Illinois at Chicago) as part of Bogotá logic seminar\n\n\nAbstract
\nThis talk deals with several issues.\n\n(1) The construction for every $
k$ of $2^{\\aleph_0}$ strongly minimal Steiner systems $2^{\\aleph_0}$ whe
re each line has length $k$ and are counterexamples to the Zilber trichoto
my.\n\n(2) The analysis of groups acting on ‘Hrushovski’ constructions
provides a detailed description of the algebraic closure of a finite set.
This beginning of a Galois theory yields for both Hrushovski’s original
constructions and Steiner systems as ternary relations:\n\n(a) failure to
admit elimination of imaginaries.\n\n(b) Restricting the $\\mu$-function
implies there is no parameter free definable binary function.\n\n(3) It is
well-known that the existence of $k$-Steiner systems with cardinality $n
< \\omega$ is dependent on number theoretic properties of $k$ and $n$. In
contrast\, there are strongly minimal $k$-Steiner systems for every $k$. A
nd 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 minimal
sets. Specifying different theories of the finite structures\, the particu
lar specification of the $\\mu$ function\, etc. yield different algebraic
and combinatorial properties of the strongly minimal generic structure.\n\
n(a) There is a class of strongly minimal sets which are neither locally m
odular nor trivial but $\\emptyset$-definable operations are ‘essentiall
y unary’.\n\n(b) Another class contains strongly minimal quasigroups whi
ch induce Steiner systems with prime power line length. The associated var
ieties (universal algebra) are permutable\, congruence regular\, and congr
uence uniform\, but not locally finite.\n\n(c) This observation leads to a
new perspective on the ample hierarchy.\n\n(5) Extending the notion of an
$(a\, b)$-cycle graph arising in the study of finite and infinite Stein t
riple systems ([CW12]) we introduce the $(a\, b)$-path graph of a block al
gebra. 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 Vi
ktor Verbovskiy [BV20] and [Bal20]. Items 2) and 3) require the separate a
nalysis of the subgroups of $aut(M)$ (the generic model of $T_\\mu$ with r
espect to the subgroup of automorphisms $G_I$ (fixing $I$ pointwise) and $
G_{\\{ I\\}}$ (fixing $I$ setwise).\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matteo Viale (Università di Torino)
DTSTART:20200911T140000Z
DTEND:20200911T153000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/15
DESCRIPTION:Title: Tameness for set theory\nby Matteo Viale (Universi
tà di Torino) as part of Bogotá logic seminar\n\n\nAbstract\nWe show tha
t (assuming large cardinals) set theory is a tractable (and we dare to say
tame) first order theory when formalized in a first order signature with
natural predicate symbols for the basic definable concepts of second and t
hird order arithmetic\, and appealing to the model-theoretic notions of mo
del completeness and model companionship.\n\nSpecifically we develop a gen
eral framework linking generic absoluteness results to model companionship
and show that (with the required care in details) a -property formalized
in an appropriate language for second or third order number theory is forc
ible from some T extending ZFC + large cardinals if and only if it is cons
istent with the universal fragment of T if and only if it is realized in t
he model companion of T.\n\nPart (but not all) of our results are conditio
nal to the proof of Schindler and Asperò that Woodin’s axiom (*) can be
forced by a stationary set preserving forcing.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:André Platzer (Carnegie Mellon University)
DTSTART:20200923T210000Z
DTEND:20200923T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/16
DESCRIPTION:Title: Logical Foundations of Cyber-Physical Systems\nby
André Platzer (Carnegie Mellon University) as part of Bogotá logic semin
ar\n\n\nAbstract\nLogical foundations of cyber-physical systems (CPS) stud
y systems that combine cyber aspects such as communication and computer co
ntrol with physical aspects such as movement in space. CPS applications ab
ound. Ensuring their correct functioning\, however\, is a serious challen
ge. Scientists and engineers need analytic tools to understand and predic
t the behavior of their systems. That's the key to designing smart and re
liable control.\n\nThis talk identifies a mathematical model for CPS calle
d multi-dynamical systems\, i.e. systems characterized by combining multip
le facets of dynamical systems\, including discrete and continuous dynamic
s\, but also uncertainty resolved by nondeterministic\, stochastic\, and a
dversarial dynamics. Multi-dynamical systems help us understand CPSs bett
er\, as being composed of multiple dynamical aspects\, each of which is si
mpler than the full system. The family of differential dynamic logics sur
veyed in this talk exploits this compositionality in order to tame the com
plexity of CPS and enable their analysis.\n\nIn addition to providing a st
rong theoretical foundation for CPS\, differential dynamic logics have als
o been instrumental in verifying many applications\, including the Airborn
e Collision Avoidance System ACAS X\, the European Train Control System ET
CS\, several automotive systems\, mobile robot navigation with the dynamic
window algorithm\, and a surgical robotic system for skull-base surgery.
The approach is implemented in the theorem prover KeYmaera X.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Artem Chernikov (University of California at Los Angeles)
DTSTART:20200916T210000Z
DTEND:20200916T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/17
DESCRIPTION:Title: Incidence counting and trichotomy in o-minimal structu
res\nby Artem Chernikov (University of California at Los Angeles) as p
art of Bogotá logic seminar\n\n\nAbstract\nZarankiewicz’s problem in gr
aph 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 $V_2$ co
ntaining $m$ and $n$ vertices\, respectively\, and such that $G$ contains
no complete bipartite subgraphs on $k$ vertices. Graphs definable in o-min
imal (or more generally distal structures) enjoy stronger bounds than gene
ral graphs\, providing an abstract setting for the Szemerédi-Trotter theo
rem and related incidence bounds. We obtain almost optimal upper and lower
bounds for hypergraphs definable in locally modular o-minimal structures\
, along with some applications to incidence counting (e.g. the number of i
ncidences between points and boxes with axis parallel sides on the plane w
hose incidence graph is $K_{k\,k}$-free is almost linear). We explain how
the exponent appearing in these bounds is tightly connected to the trichot
omy principle in o-minimal structures.\n\nJoint work with Abdul Basit\, Se
rgei Starchenko\, Terence Tao and Chieu-Minh Tran.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Silvia Barbina (The Open University)
DTSTART:20201016T140000Z
DTEND:20201016T153000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/18
DESCRIPTION:Title: The theory of the universal-homogeneous Steiner triple
system\nby Silvia Barbina (The Open University) as part of Bogotá lo
gic seminar\n\n\nAbstract\nA Steiner triple system is a set $S$ together w
ith a collection $B$ of subsets of $S$ of size $3$ such that any two eleme
nts of $S$ belong to exactly one element of $B$. It is well known that the
class of finite Steiner triple systems has a Fraïssé limit\, the counta
ble homogeneous universal Steiner triple system $M$. In joint work with En
rique Casanovas\, we have proved that the theory $T$ of $M$ has quantifier
elimination\, is not small\, has $TP_2$\, $NSOP_1$\, eliminates hyperimag
inaries and weakly eliminates imaginaries. In this talk I will review the
construction of $M$\, give an axiomatisation of $T$ and prove some of its
properties.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:John Goodrick (Universidad de los Andes)
DTSTART:20200930T210000Z
DTEND:20200930T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/19
DESCRIPTION:by John Goodrick (Universidad de los Andes) as part of Bogotá
logic seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Amador Martín Pizarro (Universität Freiburg)
DTSTART:20201023T140000Z
DTEND:20201023T153000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/20
DESCRIPTION:Title: Arithmetic progressions and complete amalgamation\
nby Amador Martín Pizarro (Universität Freiburg) as part of Bogotá logi
c seminar\n\n\nAbstract\nHindman’s theorem states that\, given a finite
colouring of the natural numbers\, there is an infinite monochromatic set
such that all the finite sums of its elements enumerated in increasing ord
er have again the same color. In particular\, there is a monochromatic tr
iangle $(x\,y\, x+y)$. A related question is Roth’s theorem on arithmeti
c progression\, which asks whether a subset $A$ of the natural numbers of
positive (upper) density contains an arithmetic progression of length 3\,
that is\, a tuple $(a\, a+b\, a+2b)$ in $A\\times A\\times A$. Finitary ve
rsions of Roth’s theorem study subsets $A$ of $\\{0\,\\ldots\, N\\}$ who
se density is greater than a fixed lower bound\, and ask whether the same
holds for sufficiently large $N$. \n\nWe will report on recent work with D
aniel Palacín on how to prove Roth’s theorem in the context of pseudo-f
inite groups with the associated counting measure\, using techniques from
geometric model theory\, and particularly\, (a version of) complete amalga
mation problems\, resonating with the independence theorem in simple theor
ies. In this talk\, we will not discuss the technical aspects of the proof
\, but present the main ideas to a general audience with a familiarity in
mathematical logic.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alf Onshuus (Universidad de los Andes)
DTSTART:20201028T210000Z
DTEND:20201028T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/21
DESCRIPTION:Title: Omega categorical dependent structures of ordinal th-r
ank\nby Alf Onshuus (Universidad de los Andes) as part of Bogotá logi
c seminar\n\n\nAbstract\nClassification problems in model theory (understa
nding and characterizing all theories in a fixed language that have certai
n properties) are a recurrent theme that has only been solved under very p
articular assumptions. Totally categorical structures can be classified by
results of Lachlan and Hrushovski. Certain classes of pseudofinite struct
ures were classified by Cherlin and Hrushovski in the book "Finite Structu
res with Few Types".\n\n\nIn this talk we will give a sketch of how these
classifications were achieved and talk about the classification problem fo
r omega categorical dependent super rosy theories. Some results we will ta
lk about include:\n\n Characterization of omega categorical th-rank one
dependent structures.\n\n Coordinatization for omega categorical depen
dent omega categorical structures of finite th-rank.\n\n Every omega ca
tegorical dependent super rosy structure has finite th-rank.\n\nA corollar
y of these results is that for any fixed countable language\, there are on
ly countably many finitely homogeneous relational super rosy dependent the
ories (modulo isomorphism).\n\n\nAll results are joint work with Pierre Si
mon. I will give definitions and intuitions for all the terms mentioned ab
ove.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Samson Abramsky (University of Oxford)
DTSTART:20201106T140000Z
DTEND:20201106T153000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/22
DESCRIPTION:Title: The logic of contextuality\nby Samson Abramsky (Un
iversity of Oxford) as part of Bogotá logic seminar\n\n\nAbstract\n(joint
work with Rui Soares Barbosa): Contextuality is a key signature of quantu
m non-classicality\, which has been shown to play a central role in enabli
ng quantum advantage for a wide range of information-processing and comput
ational tasks.\n\nWe study the logic of contextuality from a structural po
int of view\, in the setting of partial Boolean algebras introduced by Koc
hen and Specker in their seminal work.\n\nThese contrast with traditional
quantum logic a la Birkhoff--von Neumann in that operations such as conjun
ction and disjunction are partial\, only being defined in the domain where
they are physically meaningful.\n\nWe study how this setting relates to c
urrent work on contextuality such as the sheaf-theoretic and graph-theoret
ic approaches.\n\nWe introduce a general free construction extending the c
ommeasurability relation on a partial Boolean algebra\, i.e. the domain of
definition of the binary logical operations.\n\nThis construction has a s
urprisingly broad range of uses.\n\nWe apply it in the study of a number o
f issues\, including:\n\n- establishing the connection between the abstrac
t measurement scenarios studied in the contextuality literature and the se
tting of partial Boolean algebras\;\n\n- formulating various contextuality
properties in this setting\, including probabilistic contextuality as wel
l as the strong\, state-independent notion of contextuality given by Koche
n--Specker paradoxes\, which are logically contradictory statements valida
ted by partial Boolean algebras\, specifically those arising from quantum
mechanics\;\n\n- investigating a Logical Exclusivity Principle\, and its r
elation to the Probabilistic Exclusivity Principle widely studied in recen
t work on contextuality as a step towards closing in on the set of quantum
-realisable correlations\;\n\n- developing some work towards a logical cha
racterisation of the Hilbert space tensor product\, using logical exclusiv
ity to capture some of its salient quantum features.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sasha Post (Universidad de los Andes)
DTSTART:20201111T210000Z
DTEND:20201111T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/23
DESCRIPTION:Title: Lie groups and definability\nby Sasha Post (Univer
sidad 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 expans
ion of the reals can be equipped with a Lie group structure\; that is a to
pology making G a smooth variety such that the multiplication and inverse
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 expansion o
f ℝ . We cannot expect this to be true in full generality since definabl
e groups must have finitely many connected components but we still get som
e nice results for connected Lie groups. In 2016 A. Conversano\, A. Onshuu
s and S. Starchenko gave a criterion for solvable Lie groups. After settin
g the general frame of work we will recall this solvable criterion. We wil
l continue with a criterion for the case when the group is linear and we w
ill also deal with non linear Lie groups that have “nice Levi decomposit
ion”. If time allows it we will give a few words about recent work on th
e general case.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Berenstein (Universidad de los Andes)
DTSTART:20201118T210000Z
DTEND:20201118T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/24
DESCRIPTION:by Alexander Berenstein (Universidad de los Andes) as part of
Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rosario Mennuni (Universität Münster)
DTSTART:20201125T210000Z
DTEND:20201125T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/25
DESCRIPTION:Title: The domination monoid\nby Rosario Mennuni (Univers
ität Münster) as part of Bogotá logic seminar\n\n\nAbstract\nThis talk
is concerned with the interaction between the semigroup of invariant types
and the preorder of domination\, i.e. small-type semi-isolation. In the
superstable case\, the induced quotient semigroup\, which goes under the n
ame of "domination monoid"\, parameterises "finitely generated saturated e
xtensions of U" and how they can be amalgamated independently. In general\
, the situation is much wilder\, and the domination monoid need not even b
e well-defined. \n\nNevertheless\, this object has been used to formulate
AKE-type results\, can be computed in various natural examples\, and there
is heuristic evidence that well-definedness may hold under NIP. I will gi
ve an overview of the subject and present some results on these objects fr
om my thesis.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sylvy Anscombe (University of Central Lancashire & Imperial Colleg
e)
DTSTART:20201202T210000Z
DTEND:20201202T223000Z
DTSTAMP:20260422T230717Z
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://researchseminars.org/talk/SeminarioFlotanteLogMatBog/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Valderrama (Universidad Nacional de Colombia)
DTSTART:20201209T210000Z
DTEND:20201209T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/27
DESCRIPTION:by David Valderrama (Universidad Nacional de Colombia) as part
of Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marcos Mazari-Armida (Carnegie Mellon University)
DTSTART:20210127T210000Z
DTEND:20210127T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/28
DESCRIPTION:Title: Characterizing noetherian rings via superstability
\nby Marcos Mazari-Armida (Carnegie Mellon University) as part of Bogotá
logic seminar\n\n\nAbstract\nWe will show how superstability of certain cl
asses of modules can be used to characterize noetherian rings. None of the
classes of modules that we will consider are axiomatizable by a complete
first-order theory and some of them are not even first-order axiomatizable
\, but they are all Abstract Elementary Classes. This new way of looking a
t classes of modules as AECs will be emphasized as I think it can have int
eresting applications. If time permits we will see how the ideas presented
can be used to characterize other classical rings.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Javier de la Nuez González (Universidad del País Vasco)
DTSTART:20210212T140000Z
DTEND:20210212T153000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/29
DESCRIPTION:Title: Some model theory of the curve graph\nby Javier 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 fu
ndamental object in the study of its mapping class group both from the met
ric and the combinatorial point of view. I will discuss joint work with Va
lentina Disarlo and Thomas Koberda where we conduct a thorough study of cu
rve graphs from the model theoretic point of view\, with particular emphas
is in the problem of interpretability between different curve graphs and o
ther geometric complexes.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:H Jerome Keisler (University of Wisconsin-Madison)
DTSTART:20210224T210000Z
DTEND:20210224T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/30
DESCRIPTION:Title: Using Ultraproducts to Compare Continuous Structures\nby H Jerome Keisler (University of Wisconsin-Madison) as part of Bogot
á logic seminar\n\n\nAbstract\nWe revisit two research programs that were
proposed in the 1960’s\, remained largely dormant for five decades\, an
d then become hot areas of research in the last decade.\n\nThe monograph
“Continuous Model Theory” by Chang and Keisler\, Annals of Mathematics
Studies (1966)\, studied structures with truth values in $[0\,1]$\, with
formulas that had continuous functions as connectives\, sup and inf as qua
ntifiers\, and equality. In 2008\, Ben Yaacov\, Bernstein\, Henson\, and U
svyatsev introduced the model theory of metric structures\, where equality
is replaced by a metric\, and all functions and predicates are required t
o be uniformly continuous. This has led to an explosion of research with r
esults that closely parallel first order model theory\, with many applicat
ions to analysis. In my forthcoming paper “Model Theory for Real-valued
Structures”\, the ”Expansion Theorem” allows one to extend many mode
l-theoretic results about metric structures to general $[0\,1]$-valued str
uctures–the structures in the 1966 monograph but without equality.\n\nMy
paper “Ultrapowers Which are Not Saturated”\, J. Symbolic Logic 32 (1
967)\, 23-46\, introduced a pre-ordering $M \\trianglelefteq N$ on all fir
st-order structures\, that holds if every regular ultrafilter that saturat
es $N$ saturates $M$\, and suggested using it to classify structures. In t
he last decade\, in a remarkable series of papers\, Malliaris and Shelah s
howed that that pre-ordering gives a rich classification of simple first-o
rder structures. Here\, we lay the ground-work for using the analogous pre
-ordering to classify $[0\,1]$-valued and metric structures.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Caroline Terry (https://math.osu.edu/people/terry.376)
DTSTART:20210203T210000Z
DTEND:20210203T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/31
DESCRIPTION:Title: Speeds of hereditary properties and mutual algebricity
\nby Caroline Terry (https://math.osu.edu/people/terry.376) as part of
Bogotá logic seminar\n\n\nAbstract\nA hereditary graph property is a cla
ss of finite graphs closed under isomorphism and induced subgraphs. Given
a hereditary graph property $H$\, the speed of $H$ is the function which s
ends an integer $n$ to the number of distinct elements in H with underlyin
g set $\\{ 1\,...\,n\\}$. Not just any function can occur as the speed of
hereditary graph property. Specifically\, there are discrete ``jumps" in t
he possible speeds. Study of these jumps began with work of Scheinerman an
d 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 possible
speeds of a hereditary graph property were characterized. In contrast to t
his\, many aspects of this problem in the hypergraph setting remained unkn
own. In this talk we present new hypergraph analogues of many of the jumps
from the graph setting\, specifically those involving the polynomial\, ex
ponential\, 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 Laskow
ski.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Scanlon (University of California - Berkeley)
DTSTART:20210217T210000Z
DTEND:20210217T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/32
DESCRIPTION:by Thomas Scanlon (University of California - Berkeley) as par
t of Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joel Nagloo (City University of New York)
DTSTART:20210303T210000Z
DTEND:20210303T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/33
DESCRIPTION:Title: Geometric triviality in differentially closed fields\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 describing t
he 'finer' structure of geometrically trivial strongly minimal sets in $DC
F_0$. In particular\, I will explain how recent work joint with Guy Casale
and James Freitag on Fuchsian groups (discrete subgroup of $SL_2(\\mathb
b{R})$) and automorphic functions\, has lead to intriguing questions aroun
d the $\\omega$-categoricity conjecture of Daniel Lascar. This conjecture
was disproved in its full generality by James Freitag and Tom Scanlon usin
g the modular group $SL_2(\\mathbb{Z})$ and its automorphic uniformizer (t
he $j$-function). I will explain how their counter-example fits into the l
arger context of arithmetic Fuchsian groups and has allowed us to 'propose
' refinements to the original conjecture.\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alex Kruckman (Wesleyan University)
DTSTART:20210310T210000Z
DTEND:20210310T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/34
DESCRIPTION:by Alex Kruckman (Wesleyan University) as part of Bogotá logi
c seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Menachem Magidor (Hebrew University of Jerusalem)
DTSTART:20210423T140000Z
DTEND:20210423T153000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/35
DESCRIPTION:by Menachem Magidor (Hebrew University of Jerusalem) as part o
f Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juan Felipe Carmona (Universidad Nacional de Colombia)
DTSTART:20210428T210000Z
DTEND:20210428T223000Z
DTSTAMP:20260422T230717Z
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://researchseminars.org/talk/SeminarioFlotanteLogMatBog/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Julián Cano (Universidad Nacional de Colombia)
DTSTART:20210505T210000Z
DTEND:20210505T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/37
DESCRIPTION:by Julián Cano (Universidad Nacional de Colombia) as part of
Bogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/37/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Samaria Montenegro (Universidad de Costa Rica)
DTSTART:20210512T210000Z
DTEND:20210512T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/38
DESCRIPTION:by Samaria Montenegro (Universidad de Costa Rica) as part of B
ogotá logic seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Laura Gamboa (Universidad de los Andes)
DTSTART:20210519T210000Z
DTEND:20210519T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/39
DESCRIPTION:by Laura Gamboa (Universidad de los Andes) as part of Bogotá
logic seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juliette Kennedy (University of Helsinki)
DTSTART:20210528T140000Z
DTEND:20210528T153000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/40
DESCRIPTION:by Juliette Kennedy (University of Helsinki) as part of Bogot
á logic seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Isabel Müller (Imperial College - London)
DTSTART:20210609T210000Z
DTEND:20210609T223000Z
DTSTAMP:20260422T230717Z
UID:SeminarioFlotanteLogMatBog/41
DESCRIPTION:by Isabel Müller (Imperial College - London) as part of Bogot
á logic seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/SeminarioFlotanteLogMatBog/41/
END:VEVENT
END:VCALENDAR