Mathematics Seminar

 
Upcoming Seminars

Dr. Richard D'Souza (UM - Ann Arbor and Vatican Observatory)

Dr. Richard D'Souza will speak from 11:30-12:30 on Friday November 30 in MSB 421.  Pizza will be served.

Title:  Modern Computational Tools for Deciphering Galaxy Mergers: A peek into Andromeda's violent past and the fate of our Milky Way

Abstract: Galaxy merging and interactions are the key, distinctive features of our picture of galaxy
formation in a hierarchical Universe. The Andromeda Galaxy (M31), our nearest large galactic neighbour,
offers a unique opportunity to test how mergers affect galaxy properties. M31s stellar halo caused by the
tidal disruption of satellite galaxies is the best tracer of the galaxy's accretion history. Despite a decade of
effort in mapping out M31's large stellar halo, we are unable to convert M31's stellar halo into a merger
history. Here we use cosmological models of galaxy formation to show that M31’s massive and metal-
rich stellar halo containing intermediate age stars implies that it merged with a large (M* ~ 2.5 x 10^10
M_sun) galaxy ~2 Gyr ago.


I'll explain how the simulated properties of the merger debris help to interpret a broader set of
observations of M31’s stellar halo and satellites than previously considered: its compact and metal-rich
satellite M32 is the tidally-stripped core of the disrupted galaxy, M31’s rotating and flattened inner stellar
halo contains most of the merger debris, and the giant stellar stream is likely to have been thrown out
during the merger. This accreted galaxy was the third largest member of the Local Group. This may help
us understand the future fate of the Milky Way as it collides with the Large Magellanic Cloud and
eventually M31 itself in the distant future. The terms used in the abstract will be fully explained in the
lecture!

Past Seminars

Cam McLeman (UM-Flint)

Dr. Cam McLeman will speak from 12:30pm-1:30pm on Friday, February 27 in MSB 421.

Title: A Random Approach to Algebraic Number Theory.

Abstract:  The class group of a number field is a measure of the extent to which it fails to have the "unique factorization into primes" property we all know and love from the regular integers.  The study of class groups dates back to Gauss and Dedekind, and ties to many of the most famous unsolved problems in number theory, and yet so little do we know about these objects that we don't even know if the trivial group occurs as a class group infinitely often.  In this talk, we take advantage of this ignorance and share some new results you get by abandoning any hope of understanding what's going on.

James Alsup (UM-Flint)

Professor Alsup from the Physics department will speak on April 16, 2:30-3:30 on "How to build a superconductor with a black hole"

Abstract:  String theory has been a major source of excitement in theoretical physics.  The theory has developed over the last four decades in the hope of providing a "theory of everything," explaining all of matter and forces in terms of incomprehensibly tiny strings.  However, new insights have provided another pathway for the theory to develop by way of applications.  

One of the most studied applications is superconductivity.  In the lab, it has been found that if a particular metal is cooled down to a low enough temperature a current will be able to flow with absolutely no resistance.  As of now, there is no comprehensive theory explaining how this happens.

In this talk, I will discuss what string theory can offer for our understanding of superconductors and how the rules of quantum mechanics can be phrased in terms of a ten-dimensional black hole.

Wei Chen (Capital University of Economics and Business in China)

Wei Chen of Capital University of Economics and Business in China (currently visiting MSU) will be speaking on March 12th at 3:30.

Title:  Fuzzy Portfolio Optimization Based on ABC Algorithm

Abstract: We will discuss the portfolio optimization problem with real-world constraints under the assumption that the returns of risky assets are fuzzy numbers. A possibilistic semi-absolute deviation model is proposed, in which transaction costs, cardinality and quantity constraints are considered. Due to such constraints the proposed model becomes a nonlinear mixed integer programming problem and traditional optimization methods fail to find the optimal solution efficiently. Thus, an artificial bee colony (ABC) algorithm is applied to solve the corresponding optimization problem. Finally, a numerical example is given to illustrate the effectiveness of the proposed approaches.

Michael Wykes (Auto-Owners Insurance)

The UM-Flint Actuary Club presents Michael Wykes, UM-Flint alum, of Auto-Owners Insurance and the Casualty Actuarial Society, speaking on Actuarial Science:  Pricing for the Future, in Riverfront 2321 on February 6, 2014, from 4-6pm.

His first presentation on the overview of what an actuary is will be followed up with a more detailed presentation of some basic calculations that a property casualty actuary performs, and in particular on rate indication.  More specifically, he will be discussing how an insurance company can use what they know today to predict what future pricing should be, even when there is an unknown cost of claims to payout in the future. This presentation will be a great inside look at what many Actuarial Mathematics majors will be doing in their future careers.

 

Population Dynamics Graph

Hyejin Kim (MSU)

On November 13, 2013, 3:30-4:30pm in MSB 309, Hyejin Kim from MSU will speak on

Features of Fast Living : On the weak selection for longevity in degenerate birth death processes.

Deterministic descriptions of dynamics of competing species with identical carrying capacities but distinct birth, death, and reproduction rates predict steady state coexistence with population ratios depending on initial conditions. Demographic fluctuations described by a Markovian birth death model break this degeneracy. A novel large carrying capacity asymptotic theory confirmed by conventional analysis and simulations reveals a weak preference for longevity in the deterministic limit with finite time extinction of one of the competitors on a time scale proportional to the total carrying capacity.

Michael Wykes (Auto-Owners Insurance)

Michael Wykes, UM-Flint alum, actuary and manager with Auto-Owners Insurance and new Fellow of the Casualty Actuarial Society, will  be our guest speaker on November 21, 4-6 PM in 335 French Hall.

 

(Tree Frog)

Meir Shillor (Oakland University)

On October 30, 2013, 2:30-3:30pm in MSB 309, Meir Shillor from Oakland University will speak on

A Mathematical Model for Wood Frogs Population.

Matt Causley (MSU)

October 16, 2013, 2:30pm Speaker: Matt Causley (MSU)

 

"Higher order A-stable schemes for the wave equation through successive convolution".

 

In MSB 325

Chris Place (from Towers Watson)

Chris Place from Towers Watson will speak on "An Introduction to Actuarial Consulting" in 329 MSB on September 26, 2013, 1:45-2:30pm.