# Spring 2018

Below is a list of seminars sponsored by the Mathematics and Computer Science department at Adelphi University. All talks are open to the public and most talks will be accessible to undergraduate students who have had linear algebra. If you have any questions feel free to contact Branden Stone.

Unless otherwise stated, all talks will be at the following location and time:
Location: Science Building, Room 321;
Time: talks start at 1:30pm.
Feel free to suscribe to the Google Calendar for the most recent information.

Feb 9, 2018

## Title: Inroduction to the Math Behind Texas Hold'em

Abstract: The traditional depiction of poker evokes images of rough and unsavory characters, sitting in smoke-filled rooms, reading their opponents in an ultimate test of daring and will. In reality, the poker boom of the 21st Century has made poker more mainstream and given rise to a different type of poker player – analytic individuals utilizing probability, game theory, and other mathematical concepts to hone their skills and maximize their earning potential. In fact, researchers at Carnegie Mellon University developed a poker-playing AI that defeated four of the world’s top poker professionals in January 2017.

This lecture will go over some of the core fundamental principles behind the math of Texas Hold Em poker. Using the Fundamental Theorem of Poker (as expressed by David Sklansky) as our starting point, we will discuss how to evaluate the expected value of decisions we encounter in poker, when faced with incomplete information. The lecture will also introduce some common situations that arise in Texas Hold Em and their associated probabilities, and discuss methods for applying these principles to in-game situations. [PDF Poster]

Apr 6, 2018
Janet Vassilev :: University of Arizona

## Title: Winning the Hat Game

Abstract: In this talk, we will introduce the hat game and the mathematics behind winning. In fact, the main ingredients involve a little combinatorics, some linear algebra and error correcting codes. Throughout the course of the talk, volunteers will be asked to put their thinking “hats” on to play the hat game with their peers to exhibit first hand that they can win the hat game.

Apr 20, 2018
Dan Summers :: Drexel University

## Title: A RSK-Y Proposition

Abstract: Often times in Mathematics, seemingly disjoint fields are smashed together in order to make sense of problems which are difficult to solve in their own domain. The Calculus of Newton and Leibniz is founded upon the idea of using algebraic techniques to solve geometric problems which dated back to the Ancient Greeks. Linear Algebra has morphed from a method to solve systems of linear equations into a way to analyze geometric spaces by studying the functions from one to another. When one is first learning about a new branch of Mathematics, this approach might be scary, and it may seem that the amount of time needed to understand the links between different branches is not worth it, but it almost always is!

In this talk, we will discuss two areas of mathematics, Algebra and Combinatorics, which have been paired together with great results. We present two sets of combinatorial objects which are equinumerous, the Robinson–Schensted–Knuth correspondence between these two sets, and how the RSK correspondence can produce an unexpected result about the product of two polynomials. Along the way, we examine some of the algebraic and combinatorial properties of the symmetric polynomials.

# Fall 2017

Below is a list of seminars sponsored by the Mathematics and Computer Science department at Adelphi University. All talks are open to the public and most talks will be accessible to undergraduate students who have had linear algebra. If you have any questions feel free to contact Branden Stone.

Unless otherwise stated, all talks will be at the following location and time:
Location: Science Building, Room 321;
Time: talks start at 1:30pm.
Feel free to suscribe to the Google Calendar for the most recent information.

Sep 8, 2017
Johann Thiel :: New York City College of Technology

## Title: RATS Sequences in General Bases

Abstract: Conway’s RATS sequences are generated by repeating the following process: begin with a positive integer, reverse the order of the digits, add the original integer to its reverse, then sort the sum’s digits in increasing order from left to right. We consider this process for integers written in other bases besides 10 and discuss the long-term behavior of such sequences. In particular, we will examine the existence of periodic and quasiperiodic (a special type of divergence) sequences for certain bases. [PDF Poster]

Oct 20, 2017
Rick Royce :: Webb Institute

## Title: Introduction to Artificial Neural Networks

Abstract: Artificial Neural Networks (ANN) are mathematical models that are able to learn relationships between inputs and desired outputs. Their structure mimics the synaptic networks within the human brain. The knowledge learned by the network is contained in the inter-neuron connections, or weights, that are integral to the model. The value of ANN’s is that they are able to model extremely complex non-linear relationships that other models, for example polynomials, are unable to replicate. This talk will cover some basic concepts of ANN’s, discuss the mathematical development of a simplified ANN, discuss various applications, and show how ANN’s are being used in the field of Naval Architecture. [PDF Poster]

Nov 10, 2017
Eloísa Grifo :: University of Virginia

## Title: Slicing a square pizza

Abstract: It is easy to slice a pizza into triangles of the same area, but what if the pizza has a square shape? This is still easy if the number of slices is even, but what if it is odd? The problem turns out to be surprisingly difficult, and it was finally solved by Paul Monsky in 1970. What is even more surprising are the tools that Monsky used. The moral of the story is: simple sounding questions might have surprising answers, and since you don’t know what kind of mathematics you may need to solve a problem in which you are interested, you should learn everything.

Nov 17, 2017
Mauricio Nunez-Regueiro :: University of Arizona

## Title: Quantitative analysis tools to inform policy and achieve a sustainable future with big data

Abstract: Our planet is undergoing one of the most severe environmental crisis known to mankind. Multiple species are on the verge of disappearing and our changing climate is affecting how all living things experience our environment. Fortunately, the rate at which we gather data and develop novel analytical methodologies allows us to stay ahead of the curve and inform management and policy to help achieve sustainable livelihoods. In this talk, I present three case-studies where collaborators and I implement quantitative tools to uncover critical biological processes than help inform management actions and improve existing policy mechanisms. I will discuss how 1) using meta-analytic tools of published data I can assess how global biofuel production can affect biodiversity in different ecosystems. Then, I will focus on work done in one the most endangered forested ecosystems in the world: the Chaco forest. Here, I will 2) use occupancy models to analyze a deforestation policy rule that affects native mammals and 3) use spatial statistics to analyze a national-level market-based incentive that seeks to decrease deforestation and protect critical forested lands. I will finish by discussing future research directions where a professor at Adelphi University and I are collaborating to integrate mathematical models and spatial statistics to answer challenging questions in environmental sciences.

# Spring 2017

Below is a list of seminars sponsored by the Mathematics and Computer Science department at Adelphi University. All talks are open to the public and most talks will be accessible to undergraduate students who have had linear algebra. If you have any questions feel free to contact Branden Stone.

Unless otherwise stated, all talks will be at the following location and time:
Location: Science Building, Room 321;
Time: talks start at 1:30pm.
Feel free to suscribe to the Google Calendar for the most recent information.

Mar 24, 2017
Ananth Hariharan :: Indian Institute of Technology Bombay

## Title: Assumptions, Approximations and Error

Abstract: We will warm up with a simple example of mathematical modelling, highlighting the need to make assumptions to convert a real-life problem into a mathematical one. We will then see a method on how to solve an inconsistent system of linear equations approximately, and if possible, find the error.

Apr 14, 2017
Rebecca R.G. :: Syracuse University

## Title: Fiber Arts and Math: Modeling Hyperbolic Spaces

Abstract: For centuries, mathematicians thought that Euclid’s geometric postulates always worked. But sometimes they don’t… Using crocheted models, we will explore the properties of the hyperbolic plane. Come learn about the spaces that stumped mathematicians for decades, and about which Farkas Bolyai once said, “You must not attempt this approach to parallels. I know this way to its very end. I have traversed this bottomless night, which extinguished all light and joy of my life. I entreat you, leave the science of parallels alone….”

# Fall 2016

Below is a list of seminars sponsored by the Mathematics and Computer Science department at Adelphi University. All talks are open to the public and most talks will be accessible to undergraduate students who have had linear algebra. If you have any questions feel free to contact Branden Stone.

Unless otherwise stated, all talks will be at the following location and time:
Location: Science Building, Room 321;
Time: talks start at 1:30pm.
Feel free to suscribe to the Google Calendar for the most recent information.

Sep 9, 2016
Courtney Gibbons :: Hamilton College

## Title: Statistics to Algebra and Back Again

Abstract: In this talk, we’ll consider a routine problem from statistics, maximum likelihood estimation in a small coin flipping example, and find a solution using algebra. The goal of the talk is not really how to solve this problem, but to demonstrate how new courses of study in algebra arise by considering such problems from statistics. [PDF Poster]

Sep 30, 2016
Haydee Lindo :: Williams College

## Title: Into the Unknown

Abstract: This talk will be a wild ride of new and interesting mathematics. Come find out what glorious things await in this talk of unknown content. Who knows, maybe all of your wildest dreams will come true. This talk is open to students at all levels. [PDF Poster]

Oct 21, 2016
Kristen Beck :: St Mary's College of California

## Title: Irrationality: Like Blackness in the Night Sky

Abstract: Recall that every real number falls into exactly one of two categories: either it’s rational (that is, it can be expressed as a ratio, or fraction, of two whole numbers), or it’s not. Though you probably learned this seemingly fundamental fact in middle school or high school, it’s important to remember that the concept of irrationality was not always so widely accepted. In fact, the discovery of irrational numbers (by the Pythagorean philosopher Hippasus in the 5th century BC) is rumored to have greatly angered the gods. Despite the fact that mankind’s relationship with irrational numbers has come a very long way in the past two-and-a-half millennia, we still seem to favor rational numbers. It’s famously been said that rational numbers are like the stars in the night sky. In this talk, however, we will focus on the often-overlooked blackness in the night sky: the irrational numbers. And we will do this by considering “rational approximations” of them. Through this process, we will uncover a number which is more irrational than all of the others. And, what’s even more surprising: this particular number is ubiquitous in nature precisely because of its irrationality! [PDF Poster]

Nov 11, 2016
Gabriel Sosa :: Amherst College

## Title: Monomial orders uniquely determined by their induced orders

Abstract: When were are asked to write the polynomial $p(x)=3x^2+x^4+7-x$ in standard form we know our answer is $x^4+3x^2-x+7$, because the only way to order powers of $x$ is the natural one: degree wise! Complexity is introduced when we are asked to write $q(x)=2x^3yz^2-6x^4z+x^2y^3z$ in standard form and we have to define what standard form means in this setting. In this talk, we will present the three classical monomial orders (\textit{lexicographic}, \textit{degree lexicographic} and \textit{reverse lexicographic}), explore a curious property they possess (hint hint: It is the title) and discuss whether other monomial orders possess this property. [PDF Poster]

# Spring 2016

Below is a list of seminars sponsored by the Mathematics and Computer Science department at Adelphi University. All talks are open to the public and most talks will be accessible to undergraduate students who have had linear algebra. If you have any questions feel free to contact Branden Stone.

Unless otherwise stated, all talks will be at the following location and time:
Location: Science Building, Room 321;
Time: talks start at 1:30pm.
Feel free to suscribe to the Google Calendar for the most recent information.

Feb 12, 2016
Tom Enkosky :: Boston University

## Title: Flows on Graphs

Abstract: This is an expository talk on the theory of flows on a graph. We will define the flow on a directed graph and discuss several solved problems and current open problems. No prior knowledge of graph theory is necessary. [PDF Poster]

Mar 4, 2016
Johanna Franklin :: Hofstra University

## Title: A truly random talk

Abstract: Most people can intuitively classify binary sequences as “random” or “not random.” However, as mathematicians, we want a precise mathematical definition. In this talk, I will define randomness with concepts from computability theory using three different intuitive approaches as starting points: unpredictability, incompressibility, and a lack of distinguishing properties. At the end, I’ll present an example of a random sequence and talk about current directions in the field. [PDF Poster]

Mar 21, 2016
HHE Room 209, 1:25-2:15pm
Cassie Williams :: James Madison University

## Title: How elliptic curves can keep secrets and prove theorems

Abstract: Elliptic curves (and their higher dimensional analogues) have proven to be interesting, powerful, and enigmatic objects of study; on one hand elliptic curves are often a topic in undergraduate courses on group or number theory, yet there are deep open problems that arise from simple questions about their structure. In this talk we will think about how to do arithmetic on small sets, define elliptic curves in two different ways, explore their geometric and algebraic structure, and explain some of their uses within and outside of mathematics. Only the definition of a prime number will be assumed. [PDF Poster]

Apr 8, 2016
Amir Barghi :: Bard College

## Title: A Combinatorial Variation of Fermat's Last Theorem

Abstract: The equation $\left(x \mid k \right)_{n} + \left(y \mid k \right)_{n} = \left(z \mid k \right)_{n}$ is a degree-$n$, falling-factorial version of the Fermat equation, where $\left(x \mid k \right)_{n} =x(x-k)(x-2k)\cdots(x-(n-1)k)$. In this talk, I will give combinatorial interpretations of $\left(x \mid k \right)_{n}$ and $\left(z \mid k \right)_{n} - \left(y \mid k \right)_{n}$ in terms of a probabilistic game and make some observations on their combinatorial properties using these interpretations. [PDF Poster]

Apr 29, 2016
Alyssa Gottshall

## Title: Math/Computer Science Careers at NSA

Abstract: The talk will include an overview on NSA, its history, mission areas, and career fields. There will be information on student programs and full-time employment to include hiring requirements and benefits. The talk also includes pros and cons of working at NSA, then some specifics on how math is used throughout the agency. If there is time, we can discuss career paths, advancements, and some unique opportunities that the agency provides to employees. [PDF Poster]

# Fall 2015

Below is a list of seminars sponsored by the Mathematics and Computer Science department at Adelphi University. All talks are open to the public and most talks will be accessible to undergraduate students who have had linear algebra. If you have any questions feel free to contact Branden Stone.

Unless otherwise stated, all talks will be at the following location and time:
Location: Post Hall, Room 207;
Time: talks start at 1:30pm.

Sep 18, 2015
Gywn Whieldon :: Hood College

# Fall 2014

Below is a list of seminars sponsored by the Mathematics and Computer Science department at Adelphi University. All talks are open to the public and most talks will be accessible to undergraduate students who have had linear algebra. If you have any questions feel free to contact Branden Stone.

Unless otherwise stated, all talks will be at the following location and time:
Location: Post Hall, Room 207;
Time: talks start at 1:30pm.

Nov 21, 2014
Tom Enkosky :: United States Coast Guard Academy

## Title: Graph Rigidity

Abstract: A graph is a collection of vertices and edges and is often depicted visually with points and straight line segments. Suppose we draw a graph in the plane and fix the lengths of the line segments but allow the edges to pivot about the vertices. The drawing is rigid if the graph keeps its shape when the vertices are moved. In this talk we will explore some of the algebra of graph rigidity. [PDF Poster]