Zobrazeno 1 - 10
of 3 475
pro vyhledávání: '"Wands, A"'
Sudden phase transitions during inflation can give rise to strongly enhanced primordial density perturbations on scales much smaller than those directly probed by cosmic microwave background anisotropies. In this paper, we study the effect of the inc
Externí odkaz:
http://arxiv.org/abs/2410.22154
Autor:
Jackson, Joseph H. P., Assadullahi, Hooshyar, Gow, Andrew D., Koyama, Kazuya, Vennin, Vincent, Wands, David
We simulate the distribution of very rare, large excursions in the primordial density field produced in models of inflation in the very early universe which include a strong enhancement of the power spectrum. The stochastic $\delta \mathcal{N}$ forma
Externí odkaz:
http://arxiv.org/abs/2410.13683
Fast Radio Bursts (FRBs) have emerged as powerful cosmological probes in recent years offering valuable insights into cosmic expansion. These predominantly extragalactic transients encode information on the expansion of the Universe through their dis
Externí odkaz:
http://arxiv.org/abs/2407.03532
Autor:
Vennin, Vincent, Wands, David
Quantum diffusion describes the inflow of vacuum quantum fluctuations as they get amplified by gravitational instability, and stretched to large distances during inflation. In this picture, the dynamics of the universe's expansion becomes stochastic,
Externí odkaz:
http://arxiv.org/abs/2402.12672
Autor:
Ellis, John, Wands, David
Publikováno v:
`Review of Particle Physics': R.L. Workman et al. (Particle Data Group), Prog. Theor. Exp. Phys., 2022, 083C01 (2022) and 2023 update
This is a review of the current status of studies of cosmological inflation, extracted from Chapter 23 of the 2023 edition of the `Review of Particle Physics': R.L. Workman et al. (Particle Data Group), Prog. Theor. Exp. Phys., 2022, 083C01 (2022) an
Externí odkaz:
http://arxiv.org/abs/2312.13238
Autor:
Jackson, Joseph H. P., Assadullahi, Hooshyar, Gow, Andrew D., Koyama, Kazuya, Vennin, Vincent, Wands, David
The separate-universe approach gives an intuitive way to understand the evolution of cosmological perturbations in the long-wavelength limit. It uses solutions of the spatially-homogeneous equations of motion to model the evolution of the inhomogeneo
Externí odkaz:
http://arxiv.org/abs/2311.03281
Autor:
Bagui, Eleni, Clesse, Sebastien, De Luca, Valerio, Ezquiaga, Jose María, Franciolini, Gabriele, García-Bellido, Juan, Joana, Cristian, Jain, Rajeev Kumar, Kuroyanagi, Sachiko, Musco, Ilia, Papanikolaou, Theodoros, Raccanelli, Alvise, Renaux-Petel, Sébastien, Riotto, Antonio, Morales, Ester Ruiz, Scalisi, Marco, Sergijenko, Olga, Unal, Caner, Vennin, Vincent, Wands, David
In the recent years, primordial black holes (PBHs) have emerged as one of the most interesting and hotly debated topics in cosmology. Among other possibilities, PBHs could explain both some of the signals from binary black hole mergers observed in gr
Externí odkaz:
http://arxiv.org/abs/2310.19857
Cosmological $\alpha$-attractors are a compelling class of inflationary models. They lead to universal predictions for large-scale observables, broadly independent from the functional form of the inflaton potential. In this work we derive improved an
Externí odkaz:
http://arxiv.org/abs/2306.00918
Autor:
Gow, Andrew D., Assadullahi, Hooshyar, Jackson, Joseph H. P., Koyama, Kazuya, Vennin, Vincent, Wands, David
We present a non-perturbative method for calculating the abundance of primordial black holes given an arbitrary one-point probability distribution function for the primordial curvature perturbation, $P(\zeta)$. A non-perturbative method is essential
Externí odkaz:
http://arxiv.org/abs/2211.08348
Publikováno v:
JCAP01(2023)042
We explore the bounds that can be placed on interactions between cold dark matter and vacuum energy, with equation of state $w=-1$, using state-of-the-art cosmological observations. We consider linear perturbations about a simple background model whe
Externí odkaz:
http://arxiv.org/abs/2210.05363