Astrophysics Seminar

Cosmology spans an extraordinary range of scales, from the quantum origins of the universe to the first light we observe: the Cosmic Microwave Background (CMB). In this talk, we shall explore both of these extremes.

When traced back in time, the observed expansion of the universe culminates in the Big Bang singularity --- a regime where the classical theory of gravity is expected to give way to quantum physics. In the first part of this talk, we will discuss an exactly solvable model of quantum cosmology that reveals a surprising mathematical connection to the hydrogen atom. This correspondence provides rare analytical solutions, replacing the classical singularity with a quantum bounce for a positive cosmological constant, and predicting a cyclic, non-singular universe for a negative cosmological constant.

In the second part of the talk, we turn to the CMB, which provides a unique window into the physics of the early universe. While the standard cosmological model assumes these temperature fluctuations are statistically isotropic, increasingly precise observations have revealed possible anomalies. We introduce a novel geometric approach to characterizing such deviations on the sky. This provides an intuitive, real-space counterpart to the conventional harmonic methods, offering advantages for the analysis of incomplete CMb
sky.