Zobrazeno 1 - 10
of 31
pro vyhledávání: '"Alexandros Karam"'
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 83, Iss 12, Pp 1-23 (2023)
Abstract We consider cosmology with an inflaton scalar field with an additional quartic kinetic term. Such a theory can be motivated by Palatini $$R+R^2$$ R + R 2 modified gravity. Assuming a runaway inflaton potential, we take the Universe to become
Externí odkaz:
https://doaj.org/article/46597a6121594f329d107c97f099a505
Publikováno v:
Journal of High Energy Physics, Vol 2023, Iss 3, Pp 1-61 (2023)
Abstract We present an updated analysis of the first-order phase transition associated with symmetry breaking in the early Universe in a classically scale-invariant model extended with a new SU(2) gauge group. Including recent developments in underst
Externí odkaz:
https://doaj.org/article/5a045e5848d34e4ab6350152a59edd46
Publikováno v:
Physics Letters B, Vol 840, Iss , Pp 137885- (2023)
We consider the standard Einstein-Hilbert-Higgs action where the Higgs field couples nonminimally with gravity via the term ξh2R, and investigate the stability of the electroweak vacuum in the presence of gravitational corrections in both the metric
Externí odkaz:
https://doaj.org/article/b7f56686e75d41b5840f7ee0ec3dfc80
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 81, Iss 7, Pp 1-8 (2021)
Abstract We show that the observed primordial perturbations can be entirely sourced by a light spectator scalar field with a quartic potential, akin to the Higgs boson, provided that the field is sufficiently displaced from vacuum during inflation. T
Externí odkaz:
https://doaj.org/article/9e684eb6b8c94d3981d925c3570c8b0b
Publikováno v:
Journal of High Energy Physics, Vol 2020, Iss 11, Pp 1-20 (2020)
Abstract We demonstrate that light spectator fields in their equilibrium can source sizeable CMB anisotropies through modulated reheating even in the absence of direct couplings to the inflaton. The effect arises when the phase space of the inflaton
Externí odkaz:
https://doaj.org/article/29381e600f1248e3bf71c3efff80f86d
Publikováno v:
Galaxies, Vol 10, Iss 2, p 57 (2022)
We study a model of quintessential inflation constructed in R2-modified gravity with a non-minimally coupled scalar field, in the Palatini formalism. Our non-minimal inflaton field is characterised by a simple exponential potential. We find that succ
Externí odkaz:
https://doaj.org/article/f7ae77b31da94034b82cb19d50ea0bf7
Publikováno v:
Journal of Cosmology and Astroparticle Physics. 2023:013
We construct an analytically solvable simplified model that captures the essential features for primordial black hole (PBH) production in most models of single-field inflation. The construction makes use of the Wands duality between the constant-roll
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d4c7cbaaae6f858dd5a1aac348e5765c
https://doi.org/10.1088/1475-7516/2023/03/013
https://doi.org/10.1088/1475-7516/2023/03/013
Publikováno v:
Galaxies; Volume 10; Issue 2; Pages: 57
We study a model of quintessential inflation constructed in $R^2$ modified gravity with a non-minimally coupled scalar field, in the Palatini formalism. Our non-minimal inflaton field is characterised by a simple exponential potential. We find that s
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ea5db989f90b72a1f00ffbff232f952d
Publikováno v:
Journal of Cosmology and Astroparticle Physics. 2022:076
We construct a model of quintessential inflation in Palatini $R^2$ gravity employing a scalar field with a simple exponential potential and coupled to gravity with a running non-minimal coupling. At early times, the field acts as the inflaton, while
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::46f50dfaf2aa8f7f625e57d53701970b
https://doi.org/10.1088/1475-7516/2022/10/076
https://doi.org/10.1088/1475-7516/2022/10/076
Publikováno v:
Physical Review D. 104
In the framework of classical scale invariance, we consider quadratic gravity in the Palatini formalism and investigate the inflationary predictions of the theory. Our model corresponds to a two-field scalar-tensor theory, that involves the Higgs fie
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1d4938ba56b1edf3a80a7fb67d7ec54b
https://doi.org/10.1103/physrevd.104.023521
https://doi.org/10.1103/physrevd.104.023521