# Seminars

Seminars appear in decreasing order in relation to date. To find an activity of your interest just go down on the list. Normally seminars are given in english. If not, they will be marked as Spanish Only.

## When cultures collide: Preparing to teach mathematics to culturally diverse students

Event Date: Dec 15, 2020 in Education, Seminars

ABSTRACT: Mathematics education research has acknowledged the role of culture in teaching and learning, and specifically how mathematics classrooms create a context that legitimizes or invalidates various forms of knowledge. Mathematics teacher educators (MTEs) have a responsibility to expose prospective teachers (PSTs) to the different ways students’ reason about and learn mathematics and teach them how to build on students’ mathematical and cultural backgrounds. This preparation must help PSTs recognize their own cultural socialization and...

## Linear response formula for the topological entropy at the time one map of a geodesic flow on a manifold of negative curvature.

Event Date: Dec 02, 2020 in Dynamical Systems, Seminars

ABSTRACT Let be the time one map of a geodesic flow on a manifold of constant negative curvature with its Liouville measure. Consider , a family of diffeomorphisms with . In this talk we discuss about the differentiability of the map at , and we provide an explicit formula for its derivative.

## Matroids, polymatroids and submodular functions: algebra or optimization?

Event Date: Dec 02, 2020 in ACGO, Seminars

Abstract: Matroids, polymatroids and submodular functions are beautiful objects that have appeared in many areas of mathematics including algebra, geometry, topology and optimization. Consequently, they have been studied from multiple points of view. This oftentimes has the consequence that the same results are proven from different points of view and by very different communities. A notable example being their study in optimization and algebraic combinatorics. The goal of this talk is to tell this story, show how a small mixture of ideas...

## Elapsed time neural assemblies and learning processes for weak interconnections.

Event Date: Dec 01, 2020 in Differential Equations, Seminars

Abstract: Modeling neural networks is an interesting problem from both mathematical and neuroscience point of view. In particular, evolution equations describing neural assemblies derived from stochastic processes and microscopic models have become a very active area in recent years. In this context we study a neural network via time-elapsed dynamics with learning, where neurons are described by their position in brain cortex and the elapsed time since last discharge. The learning process is modeled via the change in the interconnections...

## Notas sobre expansividad positiva para semiflujos continuos.

Event Date: Nov 25, 2020 in Dynamical Systems, Seminars

ABSTRACT: En esta charla probaremos que si X es un espacio métrico y $\phi$ es un semiflujo continuo positivamente expansivo, en el sentido de Alves, Carvalho y Siqueira (2017), entonces el semiflujo $\phi$ es trivial y el espacio X es uniformemente discreto. En particular, si X es compacto, entonces es un conjunto finito.

## An optimal algorithm for strict circular seriation.

Event Date: Nov 25, 2020 in ACGO, Seminars

Abstract: Seriation is an exploratory combinatorial data analysis technique to reorder objects into a sequence along a one-dimensional continuum when the only available information among the objects is their pairwise similarity (or dissimilarity). Linear seriation aims at inferring an ordering (permutation) consistent with an underlying linear order of the data. In many cases however, the data objects may be arranged around a closed continuum yielding a rather circular underlying order. In a matrix representation, this can be visualized as a...

## Microrred de Vigilancia Ciudadana para el Mapeo de PM2.5 en la Ciudad de Concón, Chile.

Event Date: Nov 23, 2020 in Ciclo de Seminarios quincenales de la Alianza Copernicus-Chile, Seminars

## Conjetura de Ryser en hipergrafos t-intersectantes.

Event Date: Nov 19, 2020 in Seminario de Grafos, Seminars

Resumen: La conjetura de Ryser establece que el número de cover de un hipergrafo r-partito r-uniforme es a lo más (r-1)  veces el tamaño de su número de matching. En esta charla, revisaremos avances recientes en cotas para la conjetura en hipergrafos t intersectantes dadas ciertas restricciones asociadas a r y t.

## Conjuntos Asintóticamente Seccional-Hiperbólicos.

Event Date: Nov 18, 2020 in Dynamical Systems, Seminars

ABSTRACT: La noción de conjunto Asintóticamente Seccional-Hiperbólico fue introducida en [1] por C. Morales y B. San Martín. La principal característica que presentan estos conjuntos es que cualquier punto fuera de las variedades estables de sus singularidades (las cuales son hiperbólicas) poseen tiempos hiperbólicos arbitrariamente grandes. Ejemplos de sistemas que verifican esta clase de hiperbolicidad son la Herradura Singular Contractiva [1], el atractor exhibido en [2] y el atractor de Rovella [3]. En esta charla se presentarán algunas...

## Apportionment Mechanisms under Parity Constraints and the case of Chile and a new Political Constitution.

Event Date: Nov 18, 2020 in ACGO, Seminars

Abstract: How many seats should be allocated to each political party in an election? This question has a long and rich history, and plays a fundamental role in order to ensure appropriate levels of representation in the parliaments. We consider this question in the presence of types (e.g. men and women), where apart from ensuring proportionality at the party level, we also have to find an allocation which is paritary for the types. We consider two different approaches: one of them, with a greedy/local search paradigm, corresponds to a...