Zobrazeno 1 - 10
of 20
pro vyhledávání: '"Spyros Sypsas"'
Autor:
Jacopo Fumagalli, Gonzalo A. Palma, Sébastien Renaux-Petel, Spyros Sypsas, Lukas T. Witkowski, Cristobal Zenteno
Publikováno v:
Journal of High Energy Physics, Vol 2022, Iss 3, Pp 1-55 (2022)
Abstract We show that a scalar excited state with large occupation numbers during inflation leads to an enhancement of tensor modes and a characteristic pattern of order-one oscillations in the associated stochastic gravitational wave background (SGW
Externí odkaz:
https://doaj.org/article/ba69a829b1404a9188ca30f60983c4b1
Publikováno v:
Physics Letters B, Vol 760, Iss C, Pp 297-301 (2016)
We study features in the bispectrum of the primordial curvature perturbation correlated with the reconstructed primordial power spectrum from the observed cosmic microwave background temperature data. We first show how the bispectrum can be completel
Externí odkaz:
https://doaj.org/article/0ae387a465c541c7a47f5ab930c1ff14
Publikováno v:
Physical Review Letters. 129
Cosmological acceleration is difficult to accommodate in theories of fundamental interactions involving supergravity and superstrings. An alternative is that the acceleration is not universal but happens in a large localized region, which is possible
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::254f5ed56424f26ce9f20e8d5838e4fd
https://doi.org/10.1103/physrevlett.129.251104
https://doi.org/10.1103/physrevlett.129.251104
Autor:
Jacopo Fumagalli, Gonzalo A. Palma, Sébastien Renaux-Petel, Spyros Sypsas, Lukas T. Witkowski, Cristobal Zenteno
Publikováno v:
Journal of High Energy Physics
Journal of High Energy Physics volume
Journal of High Energy Physics volume
We show that a scalar excited state with large occupation numbers during inflation leads to an enhancement of tensor modes and a characteristic pattern of order-one oscillations in the associated stochastic gravitational wave background (SGWB) source
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e26e81aa469c1c14d2f7d44407ec9886
https://hal.archives-ouvertes.fr/hal-03481611
https://hal.archives-ouvertes.fr/hal-03481611
The inflationary origin of primordial black holes (PBHs) relies on a large enhancement of the power spectrum $\Delta_\zeta$ of the curvature fluctuation $\zeta$ at wavelengths much shorter than those of the cosmic microwave background anisotropies. T
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ef74cd65741ddc789557b376a5b82f2e
Publikováno v:
Physical Review
Antoniadis, Ignatios; Chatrabhuti, Auttakit; Isono, Hiroshi; Sypsas, Spyros (2020). Note on initial conditions for small-field inflation. Physical review. D-particles, fields, gravitation, and cosmology, 102(10), p. 103510. American Physical Society 10.1103/PhysRevD.102.103510
Phys.Rev.D
Phys.Rev.D, 2020, 102 (10), pp.103510. ⟨10.1103/PhysRevD.102.103510⟩
Antoniadis, Ignatios; Chatrabhuti, Auttakit; Isono, Hiroshi; Sypsas, Spyros (2020). Note on initial conditions for small-field inflation. Physical review. D-particles, fields, gravitation, and cosmology, 102(10), p. 103510. American Physical Society 10.1103/PhysRevD.102.103510
Phys.Rev.D
Phys.Rev.D, 2020, 102 (10), pp.103510. ⟨10.1103/PhysRevD.102.103510⟩
We show that initial conditions for small-field inflation can be determined quantum mechanically by introducing a suitable flattened region in the scalar potential. The inflaton is then driven towards the slow-roll attractor solution exponentially fa
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8224e21945b520d9709c9aeb00bd47fe
Autor:
Spyros Sypsas
Publikováno v:
Astronomische Nachrichten. 338:1025-1028
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5d413079e2b04e7ef52be51dcdd30052
https://doi.org/10.1002/asna.201713424
https://doi.org/10.1002/asna.201713424
Cosmic inflation may have led to non-Gaussian initial conditions that cannot be fully parametrised by 3- and/or 4-point functions. In this work, we discuss various strategies to search for primordial non-Gaussianity beyond polyspectra with the help o
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::42b6cbbd087db225b3f34c0197f83bff
Publikováno v:
Digital.CSIC. Repositorio Institucional del CSIC
instname
instname
If light enough primordial black holes (PBH) account for dark matter, then its density decreases with time as they lose mass via Hawking radiation. We show that this time-dependence of the matter density can be formulated as an equivalent $w(z)$ dark
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5a072152f3b0b4372b132f70fe6ced17
http://hdl.handle.net/10261/230575
http://hdl.handle.net/10261/230575
Publikováno v:
Physics Letters B
Physics Letters B, Elsevier, 2016, 760, pp.297-301. ⟨10.1016/j.physletb.2016.07.004⟩
Phys.Lett.B
Phys.Lett.B, 2016, 760, pp.297-301. ⟨10.1016/j.physletb.2016.07.004⟩
Phys.Lett.B, 2016, 760, pp.297-301. 〈10.1016/j.physletb.2016.07.004〉
Physics Letters B, Vol 760, Iss C, Pp 297-301 (2016)
Physics Letters B, Elsevier, 2016, 760, pp.297-301. ⟨10.1016/j.physletb.2016.07.004⟩
Phys.Lett.B
Phys.Lett.B, 2016, 760, pp.297-301. ⟨10.1016/j.physletb.2016.07.004⟩
Phys.Lett.B, 2016, 760, pp.297-301. 〈10.1016/j.physletb.2016.07.004〉
Physics Letters B, Vol 760, Iss C, Pp 297-301 (2016)
We study features in the bispectrum of the primordial curvature perturbation correlated with the reconstructed primordial power spectrum from the observed cosmic microwave background temperature data. We first show how the bispectrum can be completel
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7cb3fa069ee2adfda16a646a5e877271
https://doi.org/10.1016/j.physletb.2016.07.004
https://doi.org/10.1016/j.physletb.2016.07.004