Year: 2023
Type: article
Abstract: We study the nonperturbative evolution of inflationary fluctuations during preheating using fully nonlinear general-relativistic field-theory simulations. We choose a single-field inflationary model that is consistent with observational constraints and start the simulations at the end of inflation with fluctuations both in the field and its conjugate momentum. Gravity enhances the growth of density perturbations, which then collapse and virialize, forming long-lived stable oscillon-like stars that reach compactnesses $\mathcal{C}\ensuremath{\equiv}GM/R\ensuremath{\sim}{10}^{\ensuremath{-}3}--{10}^{\ensuremath{-}2}$. We find that $\mathcal{C}$ increases for larger field models, until it peaks due to the interplay between the overdensity growth and Hubble expansion rates. While gravitational effects can play an important role in the formation of compact oscillons during preheating, the objects are unlikely to collapse into primordial black holes without an additional enhancement of the initial inflationary fluctuations.
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Funders: Queen's College, University of Oxford, UK Research and Innovation, University of Leicester, Durham University, Institute for Data Intensive Research in Astrophysics and Cosmology, University of Washington, Engineering and Physical Sciences Research Council, Science and Technology Facilities Council
Awards: G1259507762, G1468651527, G1541806023, G1574821365, G1736745720, G1771230537, DiRAC-2.5 - the pathway to DiRAC Phase 3, G2073976794, G2076157637, G2240879383, G2309215924, G2368581224, Solving cosmological questions in strong gravity, G2724489712, G2778679777, G2843074508, The DiRAC 2.5x Facility, G3403823835, G3531124447, G3680780005, G3718830055, G4022262583, G4236677069, G4251892262, G4862659593, G5365046503, G5768834005, G5997058474, G6370610152, DiRAC-2.5 DC - Operations 2017-2020, G6420755151, G6537386148, G6800588795, G6842186148, G6873874887, G6926846737, Particles, Fields and Extended Objects, G6955735330, G7108246583, G7144766604, G7447190122, DiRAC2: 100 Tflop/s HPC cluster procurement, G7573294876, G7615445472, G7629755209, G764792286, G7702914472, G7937591081, DiRAC: Memory Intensive 2.5y, G8150249736, G8570785389, G8695159654, G8771920206, G878803593, G8962111125, G8986044568, DiRAC 2.5 Operations 2017-2020, DiRAC: Memory Intensive 2.5x
OpenAlex ID: W4384815438