Troy Raen

  • Graduate Student
300 Allen Desk #5
troy.raen@pitt.edu

Research

My research seeks to shed light on the ~95% of “stuff” in the universe that we know very little about.

Many searches for dark matter (DM, ~25%) have been done, each further constraining its properties but none providing confirmative evidence. A wide range of plausible theories remain. I investigate the effects of DM on stellar evolution, a relatively unexplored avenue for detection. The theory of asymmetric dark matter predicts a mass and cross section that can lead to non-negligible energy transport by DM in stellar cores, via scattering with nucleons. I study the effects of this energy transport on stellar lifetimes using the MESA code (Modules for Experiments in Stellar Astrophysics) and find that they are significantly reduced for stars up to ~4 solar masses in DM-rich environments. In the future, my results can be compared to observations of star clusters in various environments to constrain DM properties.

Space itself is expanding at an accelerating rate due to the presence of dark energy (DE, ~70%), one of the most surprising discoveries in recent physics. The baryon acoustic oscillation (BAO) signal is a feature imprinted in the matter distribution of the universe at early times. The original size of this feature is very well known, making it an excellent “standard ruler”, and so measurements of its size at various epochs tell us about DE by allowing us to map the universe’s expansion history. However, this ruler is large and the signal is weak. High resolution measurements in large volumes of the sky are needed. My research aims to use low resolution data and machine learning to inform strategies for obtaining high resolution measurements with efficiency.

9/2019

Co-advisor:  Dr. Jeffrey Newman

Degree

MS

Graduate Advisor

Michael Wood-Vasey