Seminarios

Futuros Eventos

2026-04-09
14:00hrs.
Seminario Fismat
Heinz Siedentop. Mathematisches Institut, Ludwig Maximilians Universität München
Tba
Sala 1
Abstract:
TBA
2026-04-08
13:40hrs.
Seminario de Matemáticas Aplicadas y Computacionales
Thomas Caussade. Phd Candidate, University College London
Regularised Numerical Steepest Descent Methods for Highly Oscillatory Integrals
Auditorio Edificio San Agustín
Abstract:
The evaluation of highly oscillatory integrals is an important topic in many areas of computational wave propagation. The Numerical Steepest Descent (NSD) method is a powerful approach to computing such integrals, which combines complex contour deformation with quadrature rules. However, for fixed frequencies NSD may lose accuracy when stationary points are close with each other, or with endpoints of the integration contour. This issue can be dealt with standard quadrature inside neighbourhoods of stationary points, in which the number of oscillations is bounded and small, combined with NSD techniques away from stationary points. In this talk, I will present a simple “black-box” interface that automates contour deformation and integration, and describe a novel framework to rigorously analyse the numerical convergence of this class of methods.
2026-04-06
16:10hrs.
Seminario de Problemas (Abiertos)
José Cuevas Barrientos. PUC
Hiperbolicidad y Green-Griffiths-Lang
Sala 1
Abstract:
En esta charla discutiremos la conjetura de Green-Griffiths-Lang que afirma que una variedad sobre un cuerpo numérico es mordélica si y solo si (su analitificación) es hiperbólica.

Eventos Pasados

2026-03-31
16:10hrs.
Seminario de Estudiantes de Doctorado en Estadística
Bryan Andres Tobar Torres. Pontificia Universidad Católica de Chile
New Contributions to Change Point Detection Based on Product Partition Models
Abstract:
Understanding how structural changes propagate across financial markets is essential for characterizing contagion and anticipating periods of instability. A standard tool in Bayesian statistics for detecting changes is the product partition model (PPM) and its multivariate extensions, which are effective at detecting abrupt shifts in distributional features, such as mean or variance. These models often rely on Gaussian assumptions, limiting their ability to detect changes only in the presence of possible symmetry or heavy tails, and implicitly assume that structural breaks occur synchronously across series. These simplifying assumptions limit their ability to capture other empirical features of financial returns, such as skewness, asymmetric relations and the gradual asynchronous transmission of shocks across interconnected markets.
 
The primary objective of this thesis is to extend the theory of multivariate change point detection within the PPM framework by introducing distributional and dependence flexibility. First, we employ the Generalized Hyperbolic (GH) distribution as the block-specific predictive distributions, enabling a representation of data dynamics that accommodates skewness and heavy-tailed behavior. Second, to capture directional contagion effects across markets, we introduce an asymmetric cross-series dependence structure using an influence matrix. Third, we extend the dependence framework to account for the delayed transmission of structural breaks by modeling the logit-transformed change point probabilities using a separable covariance structure with an explicit time-delay component. 
 
Beyond detection, the fourth objective is to develop a fully probabilistic framework for forecasting future structural changes. Building on recent advances in Bayesian online change point prediction, future change points are inferred directly from the evolving posterior distribution of the model’s own change point probabilities. This approach naturally accounts for uncertainty in both the current regime and the timing of future breaks, enabling coherent probabilistic forecasts of structural change in interconnected financial time series.

Sala 3, Facultad de Matemáticas
2026-03-31
13:30hrs.
Seminario de Geometría Algebraica
Pedro Montero. Utfsm
La conjetura de Morrison-Kawamata para variedades abelianas
sala 2
2026-03-30
16:30hrs.
Seminario de Sistemas Dinámicos
Franco Gómez. Universidad de Chile
Acciones por difeomorfismos de clase C^1 de los grupos Baumslag-Solitar en compactos son afines
Abstract:
Los grupos Baumslag-Solitar ${\rm BS}(m,n)$ generan un interés dado la variedad en sus propiedades algebraicas y su comportamiento dinámico. De hecho, C. Bonatti, A. Navas, I. Monteverde y C. Rivas mostraron que ciertos grupos solubles (entre ellos ${\rm BS}(1,n)$) solamente pueden actuar de manera afín en $[0,1]$ cuando es por difeomorfismos de clase $\mathcal{C}^1$.
 
El motivo de esta charla es revisitar resultados de la dinamica 1-dimensional en acciones de grupos ${\rm BS}(m,n)$ y probar que en intervalos compactos las acciones por difeomorfismos de los grupos ${\rm BS}(m,n)$ (que no están incluidos en el trabajo de BMNR) son conjugadas a una acción estándar afín.

Sala 2 (Sala Compartida de Matemática y Física), Departamento de Matemáticas, Campus Juan Gómez Millas, Universidad de Chile
2026-03-27
14:00hrs.
Seminario de Lógica Matemática
Benjamín Ibarra. PUC
Construcciones elementales en ZF
Abstract:
En esta sesión repasaremos algunas de las construcciones básicas de conjuntos como pares ordenados, unión, conjunto potencia, etc. introduciendo los axiomas necesarios para su definición en el sistema ZF, como también condiciones de regularidad.
Sala 1
2026-03-27
16:10hrs.
Coloquio de Matemática UC
Angélica Torres. Utfsm
Geometría algebraica en visión artificial
Abstract:
En los últimos años, herramientas provenientes de la geometría y el álgebra se han aplicado con éxito al estudio de modelos en ciencias de datos e inteligencia artificial. En esta charla nos enfocaremos en el problema Structure-from-Motion (SfM) y en cómo la geometría algebraica ha permitido comprender mejor las propiedades de algunos modelos que surgen en este contexto. El problema de SfM consiste, de manera general, en construir un modelo tridimensional de un objeto a partir de múltiples imágenes bidimensionales. Para ello se emplea información geométrica extraída de las imágenes, la cual se representa matemáticamente mediante la geometría proyectiva. El uso de ecuaciones polinomiales en este marco permite identificar los datos relevantes para la reconstrucción mediante las singularidades y dimensión de variedades algebraicas.
Auditorio Ninoslav Bralic
2026-03-26
13:30hrs.
Seminario de Geometría Algebraica
Camila Pérez. UC Chile
Baby: Blow-up y aplicaciones birracionales
sala 2
2026-03-24
16:10hrs.
Seminario de Estudiantes de Doctorado en Estadística
Fabián Gómez Solar. Pontificia Universidad Católica de Chile
Effective sample size in random fields and sampling design under fixed domain
Abstract:
At present, when performing multivariate statistical analyses at a given point in time, it is common to encounter difficulties due to the high dimensionality of the data sets involved. Spatial statistics plays a fundamental role in these contexts, as it models correlation as a function of the spatial separation among sample observations. However, a major limitation of such analyses arises from the large volumes of available data. For instance, information contained in images may lead to the analysis of massive data sets, posing substantial computational challenges. These considerations motivate the idea that it is not necessary to rely on the entire sample in order to represent the effective information it contains. In this context, the effective sample size (ESS) plays a fundamental role, as it allows the amount of independent information present in the sample to be quantified. Its implementation in spatial settings has increased considerably over the last decades. Nevertheless, in the existing literature, ESS calculations typically require the full sample information, which in many cases leads to severe computational difficulties, mainly due to the inversion of high-dimensional matrices. The objective of this research consists of two main components. The first is to redefine the calculation of the ESS, making it independent of the observed sample and instead relying on the assumed correlation model and the spatial domain to obtain a new approximation of this quantity. The second objective is to define a strategy for selecting the sampling locations that will compose the sample.
Sala 3, Facultad de Matemáticas
2026-03-24
13:30hrs.
Seminario de Geometría Algebraica
José Yáñez. Utfsm
La conjetura de Morrison-Kawamata II
sala 2
2026-03-23
1615hrs.
Santiago Number Theory and Algebra Seminar (Santas)
Sokratis Zikas. Instituto Nacional de Matemática Pura e Aplicada (Impa)
On simplicity of the Cremona groups
Abstract:
The Cremona group or rank n is the group of birational transformations of the projective space of dimension n. One of the central questions regarding these groups, dating all the way back to the 19th century and settled only recently, is whether they are simple. In this talk I will review the history of the problem, as well as the modern machinery that led to the proof of their non-simplicity. I will also demonstrate how to use this machinery to obtain an explicit free product structure in dimension 3 which, among other consequences, recovers non-simplicity in an effective way.
Sala Maryam Mirzakhani del Departamento de Matemáticas de la Facultad de Ciencias de la Universidad de Chile.https://www.mat.uc.cl/~federico.castillo/santas.html
2026-03-23
16:30hrs.
Seminario de Sistemas Dinámicos
Sebastián Donoso. Universidad de Chile
Partition Regularity for Quadratic Equations in Number Fields
Abstract:
An equation is partition regular over its domain if, for any finite coloring of that domain, there exists a monochromatic nontrivial solution. In this talk, we will review the background of this topic, focusing on the ergodic theoretic tools used to tackle such problems and present a recent joint work with A. Koutsogiannis, A. Ferré Moragues and W. Sun, concerning the partition regularity problem of quadratic equations over some number fields.
Sala de Seminarios (7° piso), Facultad de Ciencias Físicas y Matemáticas (Edificio Beauchef 851), Universidad de Chile
2026-03-20
14:00hrs.
Seminario de Lógica Matemática
Lucas Garrido. PUC
Introducción a la Teoría de Conjuntos
Abstract:
En esta sesión inaugural abordaremos la teoría de conjuntos como fundamento formal de la matemática moderna, analizando la interpretación de la noción de pertenencia a partir de la Lógica de Primer Orden y la transición del enfoque intuitivo a la teoría axiomática de Zermelo-Fraenkel.
Sala 1
2026-03-19
13:30hrs.
Seminario de Geometría Algebraica
Emilio Oyanedel. UC Chile
Baby: Superficies algebraicas
Abstract:
1.- El grupo de Picard y el Teorema de Riemann-Roch para superficies.

2.- Aplicaciones birracionales.

3.- Superficies regladas.

4.- Teorema de Castelnuovo.

5.- Superficies con p_g=0 y q>=1

6.- Dimensión de Kodaira.

7.- Cubrimientos ramificados.

8.- Superficies con k=0.

9.- Superficies con k=1 y superficies elípticas.

10.- Superficies de tipo general.


sala 2
2026-03-17
13:30hrs.
Seminario de Geometría Algebraica
José Yáñez. Utfsm
La conjetura de Morrison-Kawamata
Abstract:
El objetivo del seminario es estudiar la conjetura de Morrison-Kawamata. El cono de divisores amplios y el cono de divisores movibles de una variedad Calabi-Yau, en general, están lejos de ser poliedral. Sin embargo, la conjetura de Morrison-Kawamata predice que podemos describir estos conos como la órbita de un cono poliedral bajo la acción del grupo de automorfismos (birracionales). Desde el punto de vista geométrico, esto implica que las variedades Calabi-Yau tienen finitos modelos minimales, y finitas contracciones (birracionales o estructuras fibradas), salvo acción del grupo de automorfismos (birracionales).
 

sala 2https://www.mat.uc.cl/~urzua/
2026-03-16
16:15hrs.
Santiago Number Theory and Algebra Seminar (Santas)
Damian de la Fuente. Universidad de Talca
Sizes of Bruhat intervals.
Sala de Seminarios Maryam Mirzakhani del Departamento de Matemáticas de la Facultad de Ciencias de la Universidad de Chile
2026-03-13
16:10hrs.
Club de Matemática
Cristóbal Rivas. Universidad de Chile
Geometría y Dinámica de Grupos Ordenables.
Abstract:
En esta charla hablaremos de grupos finitamente generados, que es uno de mis objetos matemáticos favorito.  Si bien los grupos suelen presentarse de manera axiomática, veremos que ellos vienen naturalmente equipados con una rica estructura geométrica y también dinámica.  Daremos ejemplos y revisaremos algunos conceptos básicos, como la métrica de las palabras y el grafo de Cayley asociado, y otros no tan básicos, como la hiperbolicidad de Gromov y la noción de automaticidad. Pondremos énfasis en la subclase de grupos ordenables y reportaré e intentaré explicar algunos resultados recientes obtenidos en este contexto.
Auditorio Ninoslav Bralichttps://clubdematematica.mat.uc.cl/
2026-03-10
16:15hrs.
Santiago Number Theory and Algebra Seminar (Santas)
Jesse Huang. University of Waterloo
A user's guide to coherent constructive correspondence
Sala 2
2026-01-29
12:00hrs.
Coloquio de Estadística y Ciencia de Datos de la Pontificia Universidad Católica de Chile
Tamara Fernández Aguilar. Universidad Adolfo Ibáñez
Kernelised Linear Tests with Applications to Proportional Hazards Testing
Salas de usos múltiples 1 y 2 del primer piso del edificio Felipe Villanueva
2026-01-29
11:00hrs.
Coloquio de Estadística y Ciencia de Datos de la Pontificia Universidad Católica de Chile
Octavio Martínez Baltodano. Universidad Autónoma de Chile Sede Talca
Balancing Infrastructure and Human Capital: Optimal Fiscal Composition for Sustainable Growth.
Abstract:
En esta charla presentaré un trabajo que extiende el marco clásico de Alesina y Rodrik incorporando dos usos del gasto público financiado con un impuesto a la riqueza sobre el stock de capital. El modelo distingue inversión en infraestructura que aumenta la productividad del capital y gasto en capital humano que eleva la productividad del trabajo, y caracteriza la composición y la tasa de impuesto que maximizan el crecimiento de largo plazo. Además, al introducir heterogeneidad en dotaciones y decisión política por votante mediano, el trabajo muestra cómo la desigualdad puede inducir políticas fiscales alejadas del óptimo, reduciendo el crecimiento e incluso generando trampas de crecimiento.
Salas de usos múltiples 1 y 2 del primer piso del edificio Felipe Villanueva
2026-01-19
16:30hrs.
Seminario de Sistemas Dinámicos
Mélodie Andrieu. University of The Littoral Opal Coast
A Normality Conjecture on Rational Base Number Systems
Abstract:

The rational base number system, introduced by Akiyama, Frougny, and Sakarovitch in 2008, is a generalization of the classical integer base number system. Within this framework two interesting families of infinite words emerge, called minimal and maximal words.

 

We formulate the conjecture that every minimal and maximal word is normal over an appropriate subalphabet.

 

The aim of the talk is to convince the audience that the conjecture seems true and of considerable difficulty. In particular, we shall discuss its connections with several older conjectures, including the existence of Z-numbers (Mahler, 1968) and Z_p/q-numbers (Flatto, 1992), the existence of triple expansions in rational base p/q  (Akiyama, 2008), and the Collatz-inspired '4/3 problem' (Dubickas and Mossinghoff, 2009).

 

The talk is based on a joint work with Shalom Eliahou and Léo Vivion.


Sala de Seminarios (7° piso), Facultad de Ciencias Físicas y Matemáticas (Edificio Beauchef 851), Universidad de Chile
2026-01-14
15:00hrs.
Seminario de Matemáticas Aplicadas y Computacionales
Antti H. Niemi. University of Oulu
Ensuring reliability of structural simulations in the AI era
Abstract:
Artificial intelligence and machine learning are increasingly shaping how engineers analyze, design, and assess structures. In structural engineering, these tools enable optimization, rapid surrogate modeling, and decision-making under complex loading and environmental conditions. As simulations become more automated and data-driven, ensuring their reliability and robustness becomes increasingly important.
 
This talk discusses how computational mathematics supports trustworthy structural simulations in the AI era. Key topics include verification and validation, uncertainty quantification, and data quality, framed within the broader context of simulation governance. The focus is on how these ideas influence practical modeling choices and interpretation of results in engineering applications.
 
The presentation will highlight examples from advanced finite element analysis and AI-enabled structural modeling, including applications to structural optimization and reliability assessment under extreme snow loads. These examples illustrate how physics-based methods and data-driven tools can be combined effectively, while emphasizing the importance of uncertainty awareness when simulations inform safety-critical decisions.

Auditorio Edificio San Agustín
2026-01-14
13:15hrs.
Seminario Fismat
Tomasz Maszczyk. Uniwersytet Warszawski, Poland
THE LEAVITT PATH ALGEBRAS OF QUANTUM QUIVERS
Abstract:
We introduce a topos of quantum sets and study the properties of the embedding of the classical topos of sets in it. In this way, we derive  the  Birkhoff-von Neumann quantum logic and many other structures from quantum theory. In particular, we define quantum quivers in the sense of Day and Street and also Chikhladze. Then we provide a categorical derivation of the Leavitt path algebra of a regular quantum quiver and relate it to the category of stable representations of that quiver. This is based on a categorification of the Cuntz-Pimsner algebra in the context of adjoint functors, which replaces the customary use of Hilbert modules in the context of C*-algebras. Finally, we discuss the functoriality of our construction under appropriate correspondences between quantum quivers.
 

Sala 1 - Facultad de Matemáticas - Online North Atlantic Noncommutative Geometry Seminar
2026-01-12
16:30hrs.
Seminario de Sistemas Dinámicos
Nicolò Paviato. Weizmann Institute of Science
Thresholds for Poisson Limits in Symbolic Dynamics
Abstract:

About twenty years ago, Peres and Weiss generalised the classical Poisson limit theorem for appearances of words of increasing length in a sequence x. They showed that the theorem holds for almost every x with respect to the infinite uniform product measure. A natural question is whether this Poisson behaviour persists when the sequence is sampled according to a different product measure.

 

In our first result, we consider non-stationary product measures and show that there exists a quantitative threshold above which the Poisson limit theorem holds for almost every x, while below this threshold it may fail. In contrast, our second result shows that for a biased infinite product measure (a non-fair coin) the limiting behaviour is almost surely non-Poisson. This shows that the Poisson regime is specific to the equiprobable case and to small deviations from it.

 

This talk is based on works with Mike Hochman and Jon V. Kogan.


Sala 1 del Edificio Rolando Chuaqui
2026-01-08
14:00hrs.
Seminario Fismat
Fabián Belmonte. Universidad Católica del Norte
A quantization problem
Abstract:
 
In this talk we will approach the following quantization problem: Assume that the same physical system is described classically by a Hamiltonian h_0 and quantumly by a Hamiltonian $H_0$. Is it possible to find a quantization procedure mapping classical constants of motion (or conserved quantities) of h_0 into quantum constant of motion of H_0?
 
We will show that the answer is positive for two basic Hamitonians: the Harmonic Oscillator and the (flat) Laplacian. The required quantization will be the canonical Weyl quantization. We will discuss the consequences of these results and the techniques applied to prove them as well. We will provide some explicit examples of families of constants of motion in both cases.

Facultad de Matemáticas - Sala 1
2026-01-07
14:00 hrs hrs.
Seminario de Sistemas Dinámicos
Felipe Riquelme. Pontificia Universidad Católica de Valparaíso
Órbitas geodésicas y puntos límites
Abstract:

El objetivo de esta charla es explorar la relación entre la dinámica de las órbitas geodésicas en superficies hiperbólicas y la estructura de los puntos límite en el borde al infinito. En particular, presentaremos una demostración alternativa de un teorema de C. Bishop, que caracteriza la dimensión del conjunto límite en términos de los puntos límite radiales y de escape lineal. La principal ventaja de este enfoque es que permite extender el resultado a variedades de curvatura negativa de dimensión arbitraria. Este trabajo es en colaboración con D. Pizarro y S. Villarroel.
Sala 3
2026-01-07
14:45hrs.
Seminario de Sistemas Dinámicos
Adrián Esparza. Universidad Austral
Newton-Raphson de Funciones elípticas: Conectividad del Conjunto de Julia
Sala 3
2026-01-07
13:40hrs.
Seminario de Matemáticas Aplicadas y Computacionales
David Pardo. Universidad del País Vasco/euskal Herriko Unibertsitatea (Upv/ehu)
Challenges when integrating neural networks for solving parametric PDEs
Abstract:
This presentation examines the use of Physics-Informed Neural Networks (PINNs), Variational Physics-Informed Neural Networks (VPINNs), Deep Ritz methods, and First Order System Least Squares (FOSLS) combined with stochastic quadrature rules, to solve parametric partial differential equations (PDEs). It begins by introducing parametric PDEs and how these neural network techniques can be used to solve them. The presentation then delves into the challenges of solving these PDEs, including optimization, regularity, and integration. It points out that while PINNs using strong formulations may have trouble with singular solutions, they handle integration better than weak formulation methods like VPINNs or Deep Ritz. To address these integration challenges, we propose the use of unbiased high-order stochastic quadrature rules for better integration and Regularity Conforming Neural Networks to deal with complex solutions and singularities.
 
Finally, the presentation discusses the broader significance of this research for solving parametric PDE problems and suggests directions for future research, and how FOSLS and PINNs may work better than VPINNs and Deep Ritz in different cases.

Auditorio Edificio San Agustín