## Math & Stats Events: 2023 - 2024

### Math Table

**Every Monday from 12:00 - 1:30 pm****Usually held in Valentine Terrace Room A - downstairs in Valentine Hall****Watch for emails for any changes**

Math/Stat Table is an informal social time for students and faculty to get together and chat. There's no need to be majoring in Mathematics or Statistics; all are welcome. Please join us any time between noon and 1:30 pm.

**Upcoming Statistics and Data Science talks:**

The Amherst College Statistics and Data Science Colloquium is a series of talks for undergraduates.

All are welcome! The talks are intended to be accessible to students who have taken several statistics courses, although they may also provide a preview of deeper waters. The colloquium talks are usually one hour long (50 + 10 minutes for questions). We usually have a 15 minute pre-talk small gathering (with snacks and refreshments) beforehand.

**Tuesday, October 3rd, Kaitlyn Cook - Smith College**

**Topic: ***Conditional power for cluster-randomized trials with interval-censored endpoints*

Cluster-randomized trials (CRTs) of infectious disease progression often result in data where individuals belonging to the same contact networks and communities are more likely to be similar to one another. In addition, their infection status may be assessed only at intermittent study visits. The design, monitoring, and analysis of these CRTs must account for this data structure. I will discuss a flexible, simulation-based framework for conducting interim monitoring when outcomes are correlated and interval-censored and will show that this approach produces valid estimates of a trial’s ultimate probability of success (termed the conditional power) across a range of data-generating mechanisms and CRT design considerations. The framework also has high accuracy in classifying trials as futile based on available interim data. I will illustrate its use by applying it to the Botswana Combination Prevention Project, a cluster-randomized HIV prevention trial.

**Joint Math/Statistics Talk:**

**Thursday, November 9th, Katherine Moore - Amherst College**

**Topic: ***Data Cohesion: From Similarity Comparisons to Clustering (joint Math/Stat colloquium) *

We often want to observe the shape of our data and will use clustering and data visualization methods to do so. These methods typically require that our data is described with respect to a relatively small set of variables or that we provide distances among all pairs of points. For many interesting problems, however, this initial step can be quite challenging. In such a case, we may instead wish to work from a set of responses to similarity comparisons (e.g., among x, y, and z, which one is the outlier?). In this talk, I will introduce cohesion, a new measure of relative proximity that is built on this comparison framework. We’ll see how cohesion offers a perspective on our data that is quite different from distance alone and can help address challenges that arise in high-dimensional settings. I will also share some initial progress toward the development of cohesion-based methods for clustering and data visualization.

More information about the Statistics and Data Science Colloquium can be found at https://nhorton.people.amherst.edu/colloquia.

**Upcoming Math Colloquium: **

The Amherst College Math Colloquium is a series of talks for undergraduates. More information about upcoming and past talks can be found at

https://npflueger.github.io/colloquium

All are welcome! The talks are intended to be mostly accessible to students who have taken calculus, although they may also provide a preview of deeper waters. The colloquium talks are usually one hour long (50 + 10 minutes for questions). We usually have a 30 minute pre-talk small gathering (with snacks and refreshments) beforehand.

**Thursday, October 5th****Speaker: Jake Levinson - University de Montreal****Topic: Curvature and polyhedra****Abstract:**

What does it mean for a surface to be curved? One way to answer this question is in terms of triangles drawn on the surface, and there's a neat way to approach it for polyhedra -- surfaces with planar faces, like the cube and the octahedron. We'll explore this idea and also encounter an invariant called the Euler characteristic: a glimpse of the area of mathematics called topology.**Speaker Bio:**

Jake Levinson is an assistant professor of mathematics at the Université de Montréal. As an undergrad he attended Williams College (go Ephs!). He is interested in algebra, geometry and combinatorics.

**Monday, October 16th -- Public lecture****Speaker: Art Benjamin - Harvey Mudd College****4-5 pm in SCCE E110 (Lipton Lecture Hall).**

**Wednesday, October 25th****Speaker: Jessica Sidman - Amherst College**

**Wednesday, November 1****Speaker: Leo Goldmakher - Williams College**

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**Putnam Sessions**

The Putnam Competition is a national mathematics exam for undergraduate students.

It is both a challenging and fun exam, in which you will practice your problem-solving and proof-writing skills. Most of the problems require basic calculus and algebra knowledge, so first-year students are encouraged to participate.

Putnam sessions are an informal and friendly chance to meet other students, and talk about problem solving. Typically we will share some problems in advance to think about, we will have a focused discussion at the beginning of the session and then we will discuss some of the problems together and have students present solutions.

For more information contact: Prof. Ivan Contreras or Prof. Nathan Pflueger

Usually held in SMUD 206 (Dates/room subject to change)

Session 5: Thursday, October 5 (4:00-5:30 PM): Geometry

Session 6: Thursday, October 12 (4:00-5:30 PM): Matrices

Session 7: Thursday, October 19 (4:00-5:30 PM) : Combinatorics

Session 8: Thursday, October 26 (4:00-5:30 PM): Number Theory

Session 9: Thursday, November 2 (4:00-5:30 PM): Probability

Session 10: Tuesday, November 7 (4:00-5:30 PM): Algebra

Session 11: Thursday, November 16 (4:00-5:30 PM): Complex Numbers

Session 12: Thursday, November 29 (4:00-5:30 PM): Generating Functions

Exam will be held **Saturday, December 2, 2023** in SMUDD 206