Zobrazeno 1 - 10
of 256
pro vyhledávání: '"Copeland, Edmund J"'
Using lattice field simulations of the Abelian-Higgs model, we characterize the simultaneous emission of (scalar and gauge) particles and gravitational waves (GWs) by local string loops. We use {\it network} loops created in a phase transition, and {
Externí odkaz:
http://arxiv.org/abs/2408.02364
We describe a new mechanism, whose ingredients are realised in string compactifications, for the formation of cosmic (super)string networks. Oscillating string loops grow when their tension $\mu$ decreases with time. If $2H + \dot{\mu}/\mu < 0$, wher
Externí odkaz:
http://arxiv.org/abs/2406.12637
We investigate the formation and decay of oscillons during the post-inflationary reheating epoch from inflaton oscillations around asymptotically flat potentials $V(\varphi)$ in the presence of an external coupling of the form $\frac{1}{2}\, g^2 \, \
Externí odkaz:
http://arxiv.org/abs/2406.00108
We perform a detailed study of stringy moduli-driven cosmologies between the end of inflation and the commencement of the Hot Big Bang, including both the background and cosmological perturbations: a period that can cover half the lifetime of the uni
Externí odkaz:
http://arxiv.org/abs/2401.04064
Publikováno v:
Journal of Cosmology and Astroparticle Physics, Volume 2024, May 2024
A wide class of scalar field models including Quintessence and K-essence have the attractive property of tracker regimes, where the energy density stored in the field evolves so as to mimic that of the dominant background component for a period of ti
Externí odkaz:
http://arxiv.org/abs/2309.15295
Publikováno v:
Phys.Rev.D 110 (2024) 4, 043522
We study the simultaneous decay of global string loops into scalar particles (massless and massive modes) and gravitational waves (GWs). Using field theory simulations in flat space-time of isolated loops with initial length $\sim 80-1700$ times thei
Externí odkaz:
http://arxiv.org/abs/2308.08456
Primordial Black Holes (PBHs) may form in the early Universe, from the gravitational collapse of large density perturbations, generated by large quantum fluctuations during inflation. Since PBHs form from rare over-densities, their abundance is sensi
Externí odkaz:
http://arxiv.org/abs/2303.17375
Publikováno v:
Comput. Phys. Commun. 296 (2024), 109035
The ability to represent perturbative expansions of interacting quantum field theories in terms of simple diagrammatic rules has revolutionized calculations in particle physics (and elsewhere). Moreover, these rules are readily automated, a process t
Externí odkaz:
http://arxiv.org/abs/2211.14300
We carry out a thorough numerical examination of field theory monodromy inflation at strong coupling. We perform an MCMC analysis using a Gaussian likelihood, fitting multiparameter models using CMB constraints on the spectral index and the tensor to
Externí odkaz:
http://arxiv.org/abs/2205.14952
We explore a family of generalised scalar-tensor theories that exhibit self-tuning to low scale anti de Sitter vacua, even in the presence of a large cosmological constant. We are able to examine the linearised fluctuations about these vacua and comp
Externí odkaz:
http://arxiv.org/abs/2111.11448