Conveners
Cosmology
- Andrew Long (University of Chicago)
The first direct detections of gravitational waves from the mergers of binary black holes and binary neutron stars by the LIGO and VIRGO experiments have electrified the physics and astronomy communities. A clear next experimental step is an interferometer in space, which can detect lower frequency signals than a ground-based detector, including supermassive black hole binary coalescences from...
Some of the solutions to the hierarchy problem use dimensional transmutation to explain the Planck-weak hierarchy. In these models, the hierarchy is explained by exponentiation of (the inverse of) a small anomalous dimension of the coupling that characterizes the deviation of the theory from scale invariance. The confinement-deconfinement phase transition in these models can be studied using...
The recent discovery of gravitational waves from five binary black hole (BBH) mergers has given us a new way to study our universe. The origin of the black hole (BH) binaries remains unclear. In this talk, I discuss how the BH spin distribution may help us distinguish between primordial or stellar origins. Primordial black holes (PBHs) may have formed due to the collapse of large density...
Warm inflation is an interesting alternative implementation of a period of accelerated expansion and reheating in the early universe. It turns out to be easy to have a concurrent quasi-thermal radiation bath if energy is extracted from the rolling scalar field via friction. The benefits of warm inflation include automatic reheating at the end of inflation when the thermal bath begins to...
There has been considerable recent interest in a new class of non-slow roll inflationary solutions known as constant roll inflation. Constant roll solutions are a generalization of the ultra-slow roll (USR) solution, where the first Hubble slow roll parameter $\epsilon$ is small, but the second Hubble slow roll parameter $\eta$ is not. While it is known that the USR solutions represent...
Magnetic fields are observed at all scales in the universe, from planets all the way up to clusters of galaxies. To explain the presence of magnetic fields in the inter-cluster voids that are correlated on large scales, we need to consider the possibility of primordial magnetic fields. These fields, generated at early epochs of the universe like inflation or phase transitions, are subsequently...
The minimal Standard Model (SM) running of the gauge couplings gives us a hint of a Grand Unified Theory (GUT) at $M_U \sim 10^{14}$ GeV — a scale, however, too high to probe directly via collider searches. Fortunately, since the inflationary Hubble scale H can be as high as $5\times 10^{13}$ GeV $\sim M_U$, such GUT scale states can be cosmologically produced during inflation and contribute...
