activity
20242026
collaborators

7 papers

astro-ph.CO2026

Primordial Black Holes in a Radiation-Dominated Universe

Thomas W. Baumgarte, Katy Clough, Mary Gerhardinger +2

Primordial fluctuations frozen out during inflation re-enter the cosmological horizon and can collapse, leading to the formation of primordial black holes. We perform simulations o…

gr-qc2025

Restrictions on Initial Conditions in Cosmological Scenarios and Implications for Simulations of Primordial Black Holes and Inflation

Thomas W. Baumgarte, Katy Clough, John T. Giblin

Numerical relativity simulations provide a means by which to study the evolution and end point of strong over-densities in cosmological spacetimes. Specific applications include st…

astro-ph.CO2025

Primordial Black Holes from Kinetic Preheating

Peter Adshead, Eve Currens, John T. Giblin

We demonstrate that violent kinetic preheating following inflation can lead to the formation of black holes in the early Universe. In -attractor models with derivative inflaton…

hep-ph2025

Cosmological Moduli and Non-perturbative Production of Axions

Robert Wiley Deal, Leia Barrowes, John T. Giblin +3

Cosmological moduli generically come to dominate the energy density of the early universe, and thereby trigger an early matter dominated era. Such non-standard cosmological histori…

astro-ph.CO2025

The Effect of Nonlinear Gravity on the Cosmological Background During Preheating

Ryn Grutkoski, Hayley J. Macpherson, John T. Giblin +1

We use numerical relativity to study the violent preheating era at the end of inflation. This epoch can result in highly nonlinear fluctuations in density and gravitational potenti…

astro-ph.CO2024

Conversations and Deliberations: Non-Standard Cosmological Epochs and Expansion Histories

Brian Batell, Keith R. Dienes, Brooks Thomas +17

This document summarizes the discussions which took place during the PITT-PACC Workshop entitled "Non-Standard Cosmological Epochs and Expansion Histories," held in Pittsburgh, Pen…