Noticias en español
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.
Experiencias de modelización matemática en clases de matemática para no matemáticos.
Resumen Uno de los problemas que enfrentamos en nuestra práctica diaria quienes enseñamos matemática en las ciencias exactas y naturales es la constante demanda de los estudiantes ¿Y esto para qué me sirve? En vista de la diversidad de perfiles profesionales que usualmente transitan estos espacios curriculares y que existen acuerdos generales respecto a qué matemática necesitan los futuros no matemáticos, éstos no alcanzan para poder brindar respuestas que satisfagan a los estudiantes y en última instancia nuestra respuesta es ¡No te...
Long time asymptotics and soliton stability for the sine-Gordon equation.
Abstract: We compute the long time asymptotics of the sine-Gordon equation whose initial condition supports finitely many solitons(kinks/breathes). Our approach is the nonlinear steepest descent for Riemann-Hilbert problems. Through certain type of nonlinear Fourier transform, we characterize various quantities (radiation, phase shift, error estimates) by the regularity of the initial condition. We then extend our results to lower regularity spaces through a refined approximation argument. In particular, we characterize the initial condition...
On extremal problems concerning the traces of sets.
Abstract: Given two non-negative integers n and s, define m(n,s) to be the maximal number such that in every hypergraph H on n vertices and with at most m(n,s) edges there is a vertex x such that |Hx|>|E(H)|-s, where Hx is the link graph of x. This problem has been posed by Füredi and Pach and by Frankl and Tokushige. While the first results were only for specific small values of s, Frankl determined m(n,2^{d-1}-1) for all d with d|n. Subsequently, the goal became to determine m(n,2^{d-1}-c) for larger c. Frankl and Watanabe determined...
El programa de Blanchard y el Mundo Lexicográfico.
ABSTRACT: En 1989, F. Blanchard dió una clasificación de las propiedades dinámicas de la clase de beta-shifts. En dicha clasificación se mencionan condiciones necesarias y suficientes sobre la expansión ambiciosa de 1 en una base no entera para garantizar que un beta shift sea de tipo finito, sófico, cumpla la propiedad de especificación y sea sincronizado. En la presente charla hablaremos de algunos resultados parciales acerca de la generalización de esta clasificación para el mundo lexicográfico.
Pacing Mechanisms For Ad Auctions.
Abstract: Budgets play a significant role in real-world sequential auction markets such as those implemented by Internet companies. To maximize the value provided to auction participants, spending is smoothed across auctions so budgets are used for the best opportunities. Motivated by pacing mechanisms used in practice by online ad auction platforms, we discuss smoothing procedures that ensure that campaign daily budgets are consistent with maximum bids. Reinterpreting this process as a game between bidders, we introduce the notion of pacing...
Orbital (in)stability of periodic wave solutions for phi^{4n}-models.
Abstract: In this talk we shall discuss the orbital stability/instability of periodic wave solutions to the general \phi^{4n}-models, for all n\in\N. These models are (physically meaningful) generalizations of the classical phi4 model in quantum field theory. In the case n=1, we shall see that several different explicit solutions can be obtained by direct computations. However, for n>1 periodic solutions are no longer explicit. Thus, for the general case (n>1), due to the lack of explicit formulas, together with the complexity in...
Monitorización de Costas con sensores remotos.
Participación en Linea: http://vcespresso.redclara.net/@352109705c115cdd511fb968f9f4ff86# Use Explorer, Firefox o Safari.
Condiciones tipo-Pósa para potencias de ciclos hamiltonianos.
Abstract: Un resultado clásico de Pósa dice que un grafo en n vértices es hamiltoniano si su secuencia de grados d_1 \leq \dotsb \leq d_n cumple d_i >= i+1, para todo i \leq n/2. Acá, generalizamos este resultado a potencias de ciclos. Una k-potencia de un ciclo hamiltoniano es el grafo que se obtiene de un ciclo al unir los vértices a distancia a lo más k. Demostramos que si G tiene n vértices v_1, …, v_n y se cumple d(v_i) >= (k-2)n/k + i + o(n) para todo i <= n/k, entonces el grafo tiene la (k-1)-potencia de un ciclo...
Combinatorial Optimization Augmented with Machine Learning.
Abstract: Combinatorial optimization often focuses on optimizing for the worst-case. However, the best algorithm to use depends on the “relative inputs”, which is application specific and often does not have a formal definition. The talk gives a new theoretical model for designing algorithms that are tailored to inputs for the application at hand. In the model, learning is performed on past problem instances to make predictions on future instances. These predictions are incorporated into the design and analysis of the algorithm. ...
