Related Papers
Friction pressure on relativistic bubble walls
2021 •
Yann Gouttenoire
During a cosmological first-order phase transition, particles of the plasma crossing the bubble walls can radiate a gauge boson. The resulting pressure cannot be computed perturbatively for large coupling constant and/or large supercooling. We resum the real and virtual emissions at all leading-log orders, both analytically and numerically using a Monte-Carlo simulation. We find that radiated bosons are dominantly soft and that the resulting retarding pressure on relativistic bubble walls is linear both in the Lorentz boost and in the order parameter, up to a log. We further quantitatively discuss IR cut-offs, wall thickness effects, the impact of various approximations entering the calculation, and comment on the fate of radiated bosons that are reflected. 1 ar X iv :2 11 2. 07 68 6v 1 [ he pph ] 1 4 D ec 2 02 1
Cornell University - arXiv
Cosmology with the Laser Interferometer Space Antenna
2022 •
Jeremy M Wachter
Kination cosmology from scalar fields and gravitational-wave signatures
2021 •
Yann Gouttenoire
Kination denotes an era in the cosmological history corresponding to an equation of state $\omega=+1$ such that the total energy density of the universe redshifts as the sixth inverse power of the scale factor. This arises if the universe is dominated by the kinetic energy of a scalar field. It has often been motivated in the literature as an era following inflation, taking place before the radiation era. In this paper, we review instead the possibility that kination is disconnected from primordial inflation and occurs much later, inside the Standard Model radiation era. We study the implications on all main sources of primordial gravitational waves. We show how this leads to very distinctive peaked spectra in the stochastic background of long-lasting cosmological sources of gravitational waves, namely the irreducible gravitational waves from inflation, and gravitational waves from cosmic strings, both local and global, with promising observational prospects. We present model-indepe...
Gravitational waves from a dark U(1)_D phase transition in the light of NANOGrav 12.5 yr data
2021 •
Sin Kyu Kang
We study a possibility of a strong first-order phase transition (FOPT) taking place below the electroweak scale in the context of U(1)_D gauge extension of the standard model. As pointed out recently by the NANOGrav collaboration, gravitational waves from such a phase transition with appropriate strength and nucleation temperature can explain their 12.5 yr data. We first find the parameter space of this minimal model consistent with NANOGrav findings considering only a complex singlet scalar and U(1)_D vector boson. Existence of a singlet fermion charged under U(1)_D can give rise to dark matter in this model, preferably of non-thermal type, while incorporating additional fields can also generate light neutrino masses through typical low scale seesaw mechanisms like radiative or inverse seesaw.
Beyond the Standard Model co*cktail
2022 •
Yann Gouttenoire
arXiv (Cornell University)
Constraining Post-Inflationary Axions with Pulsar Timing Arrays
2023 •
Peera Simakachorn
arXiv (Cornell University)
Asymmetric Dark Matter from Gravitational Waves
2022 •
erika pierre
Physical Review D
QCD axion and gravitational waves in light of NANOGrav results
2021 •
Nicklas Ramberg
Journal of Cosmology and Astroparticle Physics
Exploring the early Universe with Gaia and Theia
Juan Garcia-Bellido
It has recently been pointed out that Gaia is capable of detecting a stochastic gravitational wave background in the sensitivity band between the frequency of pulsar timing arrays and LISA. We argue that Gaia and Theia have great potential for early universe cosmology, since such a frequency range is ideal for probing phase transitions in asymmetric dark matter, SIMP and the cosmological QCD transition. Furthermore, there is the potential for detecting primordial black holes in the solar mass range produced during such an early universe transition and distinguish them from those expected from the QCD epoch. Finally, we discuss the potential for Gaia and Theia to probe topological defects and the ability of Gaia to potentially shed light on the recent NANOGrav results.
Beyond the Standard Models with Cosmic Strings
2020 •
Peera Simakachorn
We examine which information on the early cosmological history can be extracted from the potential measurement by third-generation gravitational-wave observatories of a stochastic gravitational wave background (SGWB) produced by cosmic strings. We consider a variety of cosmological scenarios breaking the scale-invariant properties of the spectrum, such as early long matter or kination eras, short intermediate matter and inflation periods inside a radiation era, and their specific signatures on the SGWB. This requires to go beyond the usually-assumed scaling regime, to take into account the transient effects during the change of equation of state of the universe. We compute the time evolution of the string network parameters and thus the loop-production efficiency during the transient regime, and derive the corresponding shift in the turning-point frequency. We consider the impact of particle production on the gravitational-wave emission by loops. We estimate the reach of future inte...
