MSc Defense: Final Oral Examination for the Degree of Master of Science of Dylan Podkowka

Event Details

  • Date:
  • Time: 10:00 AM
  • Location: MacN 415

Thesis Title:

“Dynamical Instability of Neutron Stars in Scalar-Tensor Theories of Gravity”

Abstract

To confirm general relativity (GR) is the correct theory of gravity, even in the strong-field regime, it is necessary to constrain alternative theories using astrophysical observations. A well-studied generalization of GR is scalar-tensor theory (STT), which includes some scalar field nonminimally coupled to the metric. Although STTs have been well-constrained in some cases, using solar system experiments and pulsar timing, other regions of their parameter space remain consistent with these observations, as well as cosmological evolution. I discuss my work to further constrain STT by deducing the macroscopic properties of highly compact neutron stars that correspond with a dynamical instability in the alternative theory, but retain stability in GR. I show the expected mass, radius, and compactness for the onset of this instability given a large sample of physically possible equations of state and provide estimates for the mass and radius given current and near-future measurement precision.

Examination Committee:

  • Dr. Xiarong Qin, Chair
  • Dr. Eric Poisson, Advisor
  • Dr. Luis Lehner
  • Dr. Robert Wickham