BIG Panel: Career Paths in Math: What if You Don’t Want to Follow your PhD Advisor into Academia?
Location: Centennial Ballroom AB
Friday, March 7th | 2:00 PM – 3:00 PM
Panel Organizer and Moderator: Fadil Santosa (John Hopkins University)
Panelists: Genetha Gray (Edward Jones), Alex Gutierrez (Google), Alan Lee (Analog Devices)
Description
There are many career paths one may choose with a PhD in mathematics. One of the more obvious is to follow in your advisorâs footsteps and seek a faculty position. But there are many other options as well. In fact, over 50% of PhDs in mathematics will end up in other positions, including business, industry, and government (BIG). This panel will share their experiences based on their own careers in their field.
Undergraduate Opportunities: Building a Strong Foundation for Your Future
Location: Centennial Ballroom AB
Saturday, March 8th | 10:15 AM – 11:15 AM
Panel Organizer and Moderator: Marco V. Martinez (North Central College)
Panelists: Cristina Eubanks-Turner (Loyola Marymount University), John Rock (Cal Poly Pomona), Cristina Villalobos (University of Texas Rio Grande Valley)
Description
When you first start off in college there are many opportunities available to you. How and what should you choose from among all the options to build the strongest foundation for the next step in your career. This panel will discuss the value of internships, REUs or other research experiences on campus, and obtaining good references. This panel will also discuss the benefits of graduate studies, how to search for a graduate program, and applying to graduate school.
Graduate School: Training to be a Research Mathematician
Location: IPAM
Saturday, March 8th | 10:15 AM – 11:15 AM
Panel Organizer: Bianca Viray (University of Washington)
Panel Moderator: Anthony VĂĄrilly-Alvarado (Rice University)
Panelists: Johnny Guzman (Brown University), Jose Israel Rodriguez (University of Wisconsin – Madison), Mariana Smit Vega Garcia (Western Washington University)
Description
In graduate school, particularly the time after the core coursework, it can be easy to feel unmoored and hard to know if you are doing âthe right thingsâ. This panel will focus on demystifying this process, giving guidance on ways to uncover the hidden curriculum, to build and support your community, to push yourself to grow mathematically and as a researcher, and to take care of yourself on the journey.
Navigating Your Path: Success Strategies for Early-Career Mathematicians
Location: IPAM
Saturday, March 8th | 2:30 PM – 3:30 PM
Panel Organizer and Moderator: Nancy Rodriguez (University of Colorado, Boulder)
Panelists: Claudia Falcon (Wake Forest University), Paul Hurtado (University of Nevada, Reno), Joaquin Moraga (UCLA)
Description
There are many challenges and obligations when you first start off in your career as a research mathematician. This panel will discuss some of the many expectations on early-career mathematicians such as grant writing, setting priorities (e.g. the art of saying no), how to give good talks, strengthening your CV, and negotiating job offers. The panel will also discuss the importance of networking, finding mentors and developing a community by establishing collaborations with others.
Post-tenure: Now That You Have Tenure, What’s Next?
Location: Centennial Ballroom AB
Saturday, March 8th | 2:30 PM – 3:30 PM
Panel Organizer and Moderator: Roummel Marcia (UC Merced)
Panelists: Alvina J. Atkinson (AMS), Hector Ceniceros (UC Santa Barbara), Eun Heui Kim (South Dakota State University)
Description
For many academics, tenure is the culmination of many years of hard work and preparation. But there is also academic life post-tenure, which many do not plan as carefully. This panel will explore possibilities and challenges facing faculty who have achieved tenure. Topics will include advancing to full professor, balancing research with service commitments, exploring new research and teaching directions and administrative roles, and developing leadership skills.
Isiaha Akatlzin Rodriguez
Pregnancy, Diabetes, and Differential Equations: The Population Dynamics of Gestational Diabetes
Gestational Diabetes Mellitus (GDM) is a condition that causes high blood sugar levels in pregnant women, with an observed increased risk of pregnancy complications and developing Diabetes Mellitus (DM) post-pregnancy. Approximately 10.5 pregnancies per 100 deliveries were affected by GDM in 2020, according to the CDC, representing an increase from 4.5 pregnancies per 100 deliveries in 2000. Overall, it affects 5-9\% of pregnant women annually in the US. Despite its prevalence and increasing risk for DM, little mathematical modeling has been done to understand the population flow of women diagnosed with GDM into the diabetic population. Understanding the dynamics of a non-diabetic non-pregnant population into a newly diabetic population may serve as a foundation for researching effective interventions at the population level, before, during, and after pregnancy to reduce both the incidence of GDM and DM. We developed a model of pregnant women, focusing exclusively on women without diabetes who develop GDM. Using primarily CDC data to estimate initial parameter values, and assuming a fixed population growth rate, we observed the non-diabetic population converges to roughly 55.5 million and the diabetic population to approximately 470 thousand. The model also captures the dynamic of pregnant women who develop gestational-diabetes-related complications, and the increased risk factor of developing DM from previous GDM. Equilibrium analysis was conducted to determine the steady state of the solution to the system of ODEs, and we were able to show the positivity and uniform boundedness of the solution. Additionally, sensitivity analysis was conducted on uncertain parameters.
Tahmineh Azizi
Unraveling Cancer: Insights from Mathematical Modeling
Cancer remains one of the most pressing challenges in modern medicine, affecting millions of lives worldwide. Mathematical modeling has emerged as a valuable tool in the study of cancer, offering insights into its complex dynamics, progression, and treatment. By representing biological processes using mathematical equations, researchers can simulate and analyze various aspects of cancer growth, metastasis, and response to therapy. These models incorporate factors such as genetic mutations, cell proliferation, angiogenesis, immune response, and microenvironmental interactions to provide a comprehensive understanding of tumor behavior. Mathematical modeling also facilitates the exploration of novel treatment strategies, optimization of drug dosing regimens, and prediction of treatment outcomes. Moreover, it enables researchers to integrate data from diverse sources, including clinical studies, imaging techniques, and molecular profiling, to improve diagnostic accuracy and personalized medicine approaches. Through this work, we aim to bridge the gap between theoretical research and clinical practice, contributing to the ongoing efforts to improve cancer treatment outcomes.
Tosin Babasola
Bifurcation Analysis of the Impact of Media Campaigns on HIV Epidemic
HIV remains a global public health challenge, requiring multifaceted strategies to curb its spread and impact. Media campaigns have emerged as a powerful tool to raise awareness, promote behavior change, and encourage access to antiretroviral therapy (ART). In this work, we investigate the impact of media campaigns on influencing HIV transmission dynamics. To achieve this, we formulate an HIV transmission model that incorporates the influence of media campaigns and explore the relationship between these campaigns and disease spread. To further understand the transmission dynamics, we conduct a bifurcation analysis using center-manifold theory and establish the conditions for the occurrence of a backward bifurcation. A model simulation and sensitivity analysis are then performed using Latin hypercube sampling to demonstrate the role of the effective contact rate in driving the proliferation of the HIV epidemic.
Jose Colchado
Taxman Game’s Optimal Second Move
The taxman game begins with a list of integers from 1 to some integer N . The player may only select a number with proper divisors left on the list, which the taxman then collects. When no numbers with proper divisors left on the list remain, the taxman collects all remaining numbers, and whoever has the largest sum of numbers wins. Previous research shows that the playerâs optimal first move is the largest prime on the list, and their optimal second move is the largest square of a prime on the list if N †1000 except for N = 8, 20, and 120 . We show that this is the optimal second move for all N > 120. Beyond the second optimal move, no clear âoptimalâ move exists, making further moves impractical. Instead, we analyze Chessâs strategic framework to develop a generalized algorithm for any N.
Mont Cordero
The Tropical Degree Of A Tropical Root Surface
The field of tropical geometry arose from the desire to convert an algebraic variety \(V\) into a piecewise linear combinatorial structure Trop \(V\) that retains a lot of information about \(V\), such as degree, dimension, etc. We study tropical surfaces that arise from the root systems of type \(A\) rather than from the tropicalization of an algebraic variety. Our main result is that the tropical root surface of \(A_{n-1}\) has degree \(frac{1}{2}n(n-1)(n-2)\).}
Alvaro Cornejo
Equatorial Flow Triangulations of Gorenstein Flow Polytopes
Generalizing work of Athanasiadis for the Birkhoff polytope and Reiner and Welker for order polytopes, in 2007 Bruns and Römer proved that any Gorenstein lattice polytope with a regular unimodular triangulation admits a regular unimodular triangulation that is the join of a special simplex with a triangulated sphere. These are sometimes referred to as equatorial triangulations. We apply these techniques to give purely combinatorial descriptions of previously-unstudied triangulations of Gorensten flow polytopes. Further, we prove that the resulting equatorial flow polytope triangulations are usually distinct from the family of triangulations obtained by Danilov, Karzanov, and Koshevoy via framings. We find the facet description of the reflexive polytope obtained by projecting a Gorenstein flow polytope along a special simplex.
Isabel Corona Guevara
Stepwise Bayesian active learning for sparse polynomial chaos expansion
Polynomial chaos expansion (PCE) is a surrogate modeling approach that approximates a model’s response using an orthogonal basis of polynomials. Active learning is a machine learning approach in which a subset of data points is strategically selected from a pool to train the model. The goal is to select the most informative points to enhance performance while keeping the size of the training set low. In this work, state-of-the-art sparse Bayesian learning techniques are employed to construct a sparse PCE, integrated with Bayesian active learning (BAL) strategies to adaptively identify the training set. We introduce a step-wise BAL algorithm, where data points are iteratively added to or removed from the training set at each iteration. The proposed methods are tested on several numerical examples, comparing the performance of BAL-based models with those built using randomly selected training sets. The results demonstrate that the BAL techniques achieve superior performance with fewer training points, highlighting their effectiveness in enhancing model efficiency and accuracy.
Elsie Cortes
Using Encoder-Decoder Neural Networks to Model Optical Cloaking Devices
We use an encoder-decoder neural network to solve the forward and inverse scattering transmission problems in 2D multilayered media. This allows us to predict how waves scatter and identify the optimal parameters needed to design optical cloaking devices. By fine-tuning these parameters, we aim to manipulate light in a way that renders objects invisible. Our approach demonstrates the potential of deep learning in advancing optical cloaking technology and the design of metamaterials with controllable scattering properties. We show results for designing cloaks defined by circular boundaries and discuss extensions to more exotic boundary shapes, and how we might find more optimal cloaking device constructions.
Maria Luisa Daza Torres
Bayesian sequential approach to monitor COVID-19 variants through test positivity rate from wastewater
We present a statistical model to enhance the monitoring of COVID-19 outbreaks by correlating SARS-CoV-2 RNA concentrations in wastewater with the test positivity rate (TPR). To capture the non-autonomous nature of the prolonged pandemic, we introduce an adaptive scheme that can effectively model changes in viral transmission dynamics over time. The TPR is modeled through a sequential Bayesian approach with a Beta regression model using SARS-CoV-2 RNA concentrations measured in WW as covariable.
This approach allows us to compute the TPR based on wastewater measurements and to incorporate changes in viral transmission dynamics through the adaptive scheme. Our results demonstrate that the proposed model provides a more comprehensive understanding of COVID-19 transmission dynamics compared to relying solely on clinical case detection. The model can inform public health interventions and serve as a powerful tool for monitoring COVID-19 outbreaks.
Baboucarr Dibba
Hierarchical Neural Networks with Delay
The first goal of this talk is to introduce a new type of p-adic reactionâdifusion cellular neural network with delay. We study the stability of these networks and provide numerical simulations of their responses.
Juan Felipe Osorio Ramirez
Data-Efficient Kernel Methods for Learning Differential Equations and Their Solution Operators: Algorithms and Error Analysis
We introduce a novel kernel-based framework for learning differential equations and their solution maps that is both data-efficient and computationally efficient. Our approach is mathematically interpretable and backed by rigorous theoretical guarantees, including quantitative a priori worst-case error bounds. Furthermore, numerical benchmarks demonstrate significant improvements in both computational complexity and accuracy, achieving a reduction in relative error by one to two orders of magnitude compared to state-of-the-art methods.
Marilin Guerrero Laos
The Inhomogeneous Diffusion Equation of Wentzell Type With Discontinuous Data
Let Ω â R^N (N â„ 3)) be a bounded domain with a Lipschitz continuous boundary Î. We study the existence and uniqueness of weak solutions for a non-homogeneous parabolic diffusion problem in Ω, given by the equationu t â Au = f. Here, A is a second-order differential operator with measurable and bounded principal coefficients, not necessarily symmetric, and measurable and unbounded lower-order coefficients.
We consider non-homogeneous Wentzell-type boundary conditions on Î, expressed as N*_v(u) â Bu = g, where N*_v(u) represents the conormal derivative of u and B is a second-order operator with similar characteristics to A.
Additionally, under minimal assumptions, we obtain a priori estimates for the weak solution of the parabolic problem. These estimates depend on the norms of the data and the initial condition, allowing us to analyze the behavior and regularity of the solution under the specific Wentzell-type boundary conditions.
Alex Gutierrez Diaz
Stackelberg Network Interdiction for Vulnerability Analysis in the U.S. Leading-Edge Chip Supply Chain
This poster highlights the analysis of the U.S.’s leading chip supply chain to determine the most critical inter-country company relations in terms of their overall disruption potential. We develop a directed graph model consisting of the key players in the U.S.’s leading chip supply chain and define metrics to assess the model’s weaknesses based on revenue and geographical distance. We employ an attack-defense network interdiction model and use its dual formulation to identify the minimal set of player relations causing the highest levels of disruption based on objective maximization and minimization of revenue and distance respectively.
Kimberly Herrera
Determining Quasiperiodicity with Cup Products
Gakhar and Perea showed that quasiperiodic time series are those whose sliding window point clouds are dense in tori. The topological structure of these time series can be captured via persistence diagrams, however there exist time series with persistence diagrams which have seems to have the same topological features as quasiperodic functions but whose sliding window point clouds are not dense in a torus; we consider these âfake quasiperiodicâ functions. To distinguish between the quasiperiodic functions and the âfake quasiperiodicâ functions, we propose an algorithm that incorporates both persistent cohomology and cup products, which assigns the to a persistence diagram what we call a quasiperiodic score. This algorithm achieves a more precise detection of quasiperiodicity and demonstrates the robustness when applied to various dissonant signals even when different kinds of noise was added.
Victoria Kala
A Thermomechanical Hybrid Incompressible Material Point Method
We present a novel hybrid incompressible flow/material point method solver for simulating the combustion of flammable solids. Our approach utilizes a sparse grid representation of solid materials in the material point method portion of the solver and a hybrid Eulerian/FLIP solver for the incompressible portion. We utilize these components to simulate the motion of heated air and particulate matter as they interact with flammable solids, causing combustion-related damage. We include a novel particle sampling strategy to increase Eulerian flow accuracy near regions of high temperature. We also support control of the flame front propagation speed and the rate of solid combustion in an artistically directable manner. Solid combustion is modeled with temperature-dependent elastoplastic constitutive modeling. We demonstrate the efficacy of our method on various real-world three-dimensional problems, including a burning match, incense sticks, and a wood log in a fireplace.
John Lentfer
The sign character of the triagonal fermionic coinvariant ring
We determine the trigraded multiplicity of the sign character of the triagonal fermionic coinvariant ring \(R_n^{(0,3)}\). As a corollary, this proves a conjecture of Bergeron (2020) that the dimension of the sign character of \(R_n^{(0,3)}\) is \(n^2-n+1\). We also give an explicit formula for double hook characters in the diagonal fermionic coinvariant ring \(R_n^{(0,2)}\). Finally, we give a multigraded refinement of a conjecture of Bergeron (2020) that the dimension of the sign character of the \((1,3)\)-bosonic-fermionic coinvariant ring \(R_n^{(1,3)}\) is \(\frac{1}{2}F_{3n}\), where \(F_n\) is a Fibonacci number.
Gyivan Lopez-Campos
Borsuk and VĂĄzsonyi problems through Reuleaux polyhedra
The Borsuk conjecture and the VĂĄzsonyi problem are two attractive and famous questions in discrete and combinatorial geometry, both based on the notion of diameter of bounded sets. In this poster, we present an equivalence between the critical sets with Borsuk number 4 in \(\mathbb{R}^3\) and the minimal structures for the VĂĄzsonyi problem by using the well-known Reuleaux polyhedra. The latter lead to a full characterization of all finite sets in \(\mathbb{R}^3\) with Borsuk number 4.
The proof of such equivalence needs various ingredients, in particular, we proved a conjecture dealing with strongly critical configuration for the VĂĄzsonyi problem and showed that the diameter graph arising from involutive polyhedra is vertex (and edge) 4-critical. This is a joint work with DĂ©borah Oliveros and Jorge RamĂrez AlfonsĂn.
Thomas Martinez
Affine Deodhar Diagrams and Rational Dyck Paths
Given a bounded affine permutation f, we introduce affine Deodhar diagrams for f, similar to affine pipe dreams introduced by Snider. We explore combinatorial moves between these diagrams and use these moves to establish a bijection between Deodhar diagrams and restricted Dyck paths for a special class of bounded affine permutations. This resolves an open problem posed by Galashin and Lam.
Haily Martinez
Congruences in arithmetic progression for lecture hall partitions
In 1997 Bousquet-Melou and Erikkson proved a finite version of Eulerâs âodd = distinctâ partitions theorem and thus lecture hall partitions were discovered. For positive integers n and m, this finite version can be stated as follows: p(nâodd parts,none larger than 2m-1)=LH_m(n), where LH_m denotes the lecture hall partitions of n with length m. This presentation will discuss families of Ramanujan-like congruences in arithmetic progression for the lecture hall partitions. For example, for all integers
k>0, LH_3 (15k-1)âĄ0(mod 5)
LH_4 (105k-1)âĄ0(mod 7)
LH_3 (3465k-7)âĄ0(mod 11)
These results have similarities to congruences for p(n,d), the function enumerating the partitions of n into at most d parts, established by Kronholm in 2005.
Efren Mesino Espinosa
Generalized Quasi-linear Fractional Venttsel’-Type Problems Over Non-Smooth Regions
We investigate the solvability and establish a priori estimates for the generalized elliptic quasi-linear fractional problem involving the regional fractional p-Laplace operator with Neumann or Robin boundary conditions. First, we prove the existence and uniqueness of weak solutions for the problem, and we show that such solutions are globally bounded. Moreover, we establish a priori estimates for the difference of weak solutions of our problem. Additionally, we present results on inverse positivity and a weak comparison principle.
Cesar Meza
Generic torus orbit closures in matrix Schubert varieties
T-varieties are affine varieties equipped with an action of a torus T. The complexity of a normal T-variety is the codimension of the largest T-orbit. In this poster, we focus on the complexity of a specific class of T-varieties called matrix Schubert varieties. Introduced by Fulton in 1992, matrix Schubert varieties consist of square matrices satisfying certain constraints on the ranks of their submatrices. The cross product of n-by-n diagonal invertible matrices is a torus that acts on certain affine subvarieties of a matrix Schubert variety. Building up from results by EscobarâMĂ©szĂĄros and Donten-BuryâEscobarâPortakal, we show that for a fixed n, the complexity of these subvarieties of a matrix Schubert variety with respect to this action can be any integer between 0 and (n â 1)(n â 3), except 1.
Kayode Oshinubi
Accounting for spatial variation in climatic factors predicts spatial variations in mosquito abundance in the desert southwest
Mosquito population dynamics are particularly sensitive to local weather conditions, and previous studies have demonstrated that mosquito-borne disease outbreaks can be spatially concentrated. In this study, we build a climate-driven model of mosquito population dynamics, and we compare whether predictions of mosquito abundance at the county-scale are improved by accounting for sub-county climate variation. First, we built a simple mechanistic model of mosquito population dynamics that is influenced by both daily temperature and 30-day accumulated precipitation. Then, we use clustering algorithms to divide Maricopa County into clusters with similar variation in temperature and precipitation, combining zip codes into clustered communities. Our goal is to evaluate the effectiveness of this cluster-based modeling for predicting mosquito abundance in Maricopa County. Therefore, we compare two clustering techniques: one based only on neighbor distance, and the method based on time series of climate data. We then use MCMC to fit the mechanistic model using averaged climate data in each cluster. We show how the simple, climate-forced modeling does a good job at estimating detailed mosquito abundance trajectories throughout a ten-year period. Most importantly, we discovered that this spatial variation in climate improves the fit of the model to the data, emphasizing how small-scale variation cause heterogeneities in mosquito population dynamics. This study demonstrates that constructing models at a small scale improves explanation of mosquito population dynamics and we anticipate that such modeling efforts will also aid in using weather forecasts to predict mosquito populations, aiding in efforts to control the spread of infectious disease.
Kimberly Savinon
An a posteriori error field calculation of the finite element method
Many computer simulations use numerical methods to estimate the solutions of PDE systems. Some of the most popular methods are finite difference methods (FDM), finite element methods (FEM), and finite volume methods (FVM). In application settings, the analytical solution is not available, so there is an unknown numerical error. Auxiliary computations may be used to assess this error, known as a posteriori error estimates. There are many varieties of such error estimates; one class of interest computes entire fields of error that can be used to create a detailed picture of the error over the computational domain. Direct error field calculations are not common or well-understood for FEM. It will be shown how to adapt techniques developed with FDM and FVM to compute a posteriori error fields using FEM. A computational example will be provided to illustrate the quality of the error field even where the solution lacks differentiability and yields a complex error structure that is difficult to capture.
Kevin D Silva Perez
Diffusion over Bronchial Trees: Construction and Approximation Results
In this paper following the results and notions held in [1] about a ramified domain class with fractal boundary Îâ, we construct a pair of successions an â H d(Îâ), bn â H d(Îâ) such that 0 < bn †H d(Îâ) †an < â. On the other hand, we extend the fine regularity theory for weak solutions in a parabolic diffusion problem (1) with variation in the pa- rameters (a, Ξ ) and Dirichlet and Robin boundary conditions (in the generalized sense) on a d-set with certain fractal properties, where sobolev spaces can be defined W1,p, for an appropriate d.
u_t – Îu + αu = f(x,t) en Ω Ă (0,â).
(âu/âΜ) + ÎČu = g(x,t) en Îâ Ă (0,â).
u = 0 en (âΩ \ Îâ) Ă (0,â).
u(xâ,t) = uâ en (Ω \ (âΩ \ Îâ)) Ă (0,â).
Moreover, if a < aâ, then Ω is a (Δ,ÎŽ)-domain, and in this case we use the results of [2] to check that the weak solutions are Holder continuous over Ω, and by taking a = aâ, Ω is weakened to the point of not being a (Δ,ÎŽ)-domain, and consequently we prove that the solutions can be globally bounded. Thus, from functional methods we state existence, uniqueness and boundedness results for the solutions of the above class of diffusion prob- lems, and we point out some applications of interest.
Antonio Torres
Slicing Convex Polytopes
We investigate the sections of convex polytopes obtained by intersecting them with affine hyperplanes. Our work focuses on establishing tight bounds on the maximum number of vertices attainable in these slices, as well as analyzing the sequence of vertex counts from all possible slices and the gaps within that sequence. In particular, we emphasize key polytopes such as the cyclic polytope and hypercubes.