# News

## Murong Xu Ph.D Defense

A study on Graph Coloring and Digraph Connectivity

Date: 3/29/2017

Time: 3:00PM-5:00PM

Place: 315 Armstrong Hall

All are welcome.

## Yang Wu Qualifier

Eulerian Subgraphs and Hamiltonian Properties of line graphs

Date: 02/20/2018

Time: 3:30PM-5:00PM

Place: 315 Armstrong Hall

Abstract: View

All are welcome.

## Actuarial Club Hosts BrickStreet VP

T. Kirk Aguirre will cover the following topics:

- Introduce company, such as products, internship opportunities, actuarial rotation program, and possible full-time positions
- Talk about important qualifications and skills needed for the entry level actuary, and opportunity/study time/incentives for encourage employees to continue pass the actuarial exams
- Future demand in the actuary profession
- Other information related to the actuary profession/insurance company
- Q&A

Date: 11/14/2017

Time: 3:30PM-4:30PM

Place: 207 Armstrong Hall

All are welcome.

## Dan Solomon Ph.D Defense

A New Compactification for Celestial Mechanics.

Date: 11/3/2017

Time: 3:30PM-5:00PM

Place: 315 Armstrong Hall

All are welcome.

## Math Prof, Neutron Stars

For the first time, scientists have directly detected gravitational waves—ripples in space and time—from the spectacular collision of two neutron stars. Light from the collision was also observed by telescopes, marking the first time that a cosmic event has been viewed in both gravitational waves and light.

## Tim McCarty Prospectus

How Experts Conceptualize Differentials

Abstract: The differential is a symbol found in many mathematical contexts, including notations for differentiation and integration. But even though such notations are common, there can be many interpretations of the purposes or roles of the differentials in these notations. I wished to interview mathematicians and physicists to see how they interpreted differentials in a variety of settings and conducted two small studies to that end. I shall begin my talk by discussing a brief history of differential notation, the conceptualizations of the differential suggested by RUME and PER literature, and the idea of concept image (Tall & Vinner, 1981), which has shaped my research. I shall then present the results of my studies, which show that not only is there no formal concept definition of the differential evoked by all subjects, but there is also the suggestion that mathematicians and physicists view differentials contrarily.

Date: 10/16/2017

Time: 4:00PM-5:30PM

Place: 203 Armstrong Hall

## Kristen Murphy Prospectus

Abstract: Spatial reasoning is required for many topics in undergraduate mathematics; graphing, curve sketching, transformations of functions, manipulation of objects in 3D, etc. Many topics covered in calculus require the student to use some sort of spatial skill to make informed decisions related to the problem at hand. However, unlike topics such as algebra and trigonometry, there are few programs that test students on their spatial reasoning skills before entering a course and then provide remediation if the student is lacking in that area. Some engineering programs do such testing and provide remediation, but no literature can be found on mathematics programs doing this. This study will employ haptic technology, computer-based technology that provides touch feedback, in order to determine if students who score low on a spatial skills test can be helped to refresh or acquire the skills they lack that will be necessary for later success in the calculus courses.

Date: 9/6/2017

Time: 4:00PM-5:30PM

Place: 119 Armstrong Hall

## Student Receives $5000 Actuarial Scholarship

Congratulations to Maleesha Ebanks!

She received Milliman Actuarial scholarship $5000, which is targeted toward minority students that are underrepresented in the actuarial and professional services fields. She passed the first actuarial exam in July 2016 after taking Math 363 and attending the additional weekly practice session hosted by Actuarial Student Club. She said this scholarship has given her more motivation for passing next actuarial exam in December 2017. She is currently taking Math 364, which prepares her to take the second actuarial exam FM.

## Thomas Adams Masters Project

Algorithms for Computing the Inverse of a Curl

Abstract: In order to transform data from a numerical simulation of binary black holes in which only the magnetic field B is computed, to another simulation in which only the vector potential A is computed, ∇ × A = B must be solved to generate a vector potential from the known magnetic field vector. We implement multiple methods for solving this equation based on finite difference numerical representations of the equation. One method of solving this equation directly is to solve the problem sequentially point-by-point, using the solution at previous points as constraints.

Two other methods of solving this problem focus on taking the curl of both sides of the equation and solve the resulting Poisson's equation. The first of these methods is to set up a large but very sparse matrix and solve globally using Gaussian Elimination. The second of these methods is perform a multigrid solve by setting up the problem on grids of multiple resolutions and solving on each level using an iterative technique.

Of the two Poisson's equation methods the multigrid solver is determined through testing to have superior computational scaling for very large magnetic fields to the global solver. It also holds the advantage over the direct point-by-point method of being able to easily incorporate adaptive mesh refinement which is needed for solving the problem on the incredibly large magnetic fields used by the simulations. This leads to the conclusion that the multigrid method should be the primary focus for testing and implementation.

Date: 7/12/2017

Time: 3:30PM-4:30PM

Place: 415 Hodges

All are welcome.

## Jian Cheng Defense

Integer Flows and Circuit Covers of Signed Graphs

Abstract: View

Date: 7/7/2017

Time: 10:00AM-12:00PM

Place: 207 Armstrong Hall

All are welcome.

## Pages