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Physics Seminar 11-21-2008


 

Neutralinos in Nonstandard Cosmologies
-Stephanie Schuk-
Physics Department, Creighton University

 

The neutralino is one of the best dark matter candidates that yield the correct relic density. Recent experiments have been trying to detect neutralinos directly as well as indirectly. The constraints imposed on these experiments have limited the parameter space available to find neutralinos. The parameters are constrained because of the limitations in standard cosmology. The observed relic density and the one found through standard cosmologies are also not in agreement with each other. Exploring nonstandard cosmologies is one way to allow experiments greater parameter space when trying to detect neutralinos. We are focusing on cosmological models in which the early universe was dominated by a scalar field that then decays into the neutralino giving rise to the radiation dominated era. Doing this yields a wider range of dark matter densities and a bigger parameter space. We are doing a theoretical analysis of the properties of the scalar field, how the scalar field will change with the evolution of the universe, and its effect on the neutralino relic density.

 


Observations of Quasar 3C279 using space based interferometry

-Niraj Pant-

Physics Department, Creighton University

 

I will present observations of quasar 3C279 using space based interferometry. Quasars are among the most powerful and most distant objects in the universe. Quasars consist of the energetic region surrounding a supermassive black hole at the center of a distant galaxy that can accelerate jets of plasma up to speeds very close to the speed of light. By using a network of radio telescopes known as an interferometer, much sharper views are obtained of these distant objects. The goals of my research are to measure the physical conditions near the supermassive black hole and to understand the physical processes at work in these extreme environments. I will present images I made at 1.6 GHz and 5 GHz and some modeling that I have conducted.

Date of Event: 
Friday, November 21, 2008 - 12:30
Location: 
Hixson Lied G59
Contact info: 
Dr. Patricia Soto

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