Zobrazeno 1 - 10
of 25
pro vyhledávání: '"Ricardo Z. Ferreira"'
Autor:
Ricardo Z. Ferreira, Carlo Heissenberg
Publikováno v:
Journal of High Energy Physics, Vol 2021, Iss 2, Pp 1-48 (2021)
Abstract We discuss modifications to the Hawking spectrum that arise when the asymptotic states are supertranslated or superrotated. For supertranslations we find nontrivial off-diagonal phases in the two-point correlator although the emission spectr
Externí odkaz:
https://doaj.org/article/2904724ef4fb400b9900a557371998e3
We present a model-independent search for the gravitational wave background from cosmic domain walls (DWs) in the NANOGrav 12.5 years dataset and International PTA Data Release 2. DWs that annihilate at temperatures $\sim 20-50~\text{MeV}$ with tensi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9186bc79e38cfefce543b6db7dc84b24
http://arxiv.org/abs/2204.04228
http://arxiv.org/abs/2204.04228
We show that in theories of axionlike particles (ALPs) coupled to electrons at tree-level, the one-loop effective coupling to photons is process dependent: the effective coupling relevant for decay processes, $g_{a\gamma}^{\text{(D)}}$, differs signi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f4aa1af026b29d6c401be10dd4d78f94
Publikováno v:
Physical Review Letters
The axion solution to the strong CP problem is delicately sensitive to Peccei-Quinn breaking contributions that are misaligned with respect to QCD instantons. Heavy QCD axion models are appealing because they avoid this so-called "quality problem". W
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b871e78c1c5c993ce7483fa6353c3732
https://pubmed.ncbi.nlm.nih.gov/35476463
https://pubmed.ncbi.nlm.nih.gov/35476463
Publikováno v:
Physical Review
We perform for the first time a dedicated analysis of cosmological constraints on Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) QCD axion models. Such constructions are especially interesting in light of the recent xenon1texcess and of hints from stellar
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4848cdbb0e014487d418c5bfee514dcf
http://repo.scoap3.org/api
http://repo.scoap3.org/api
The recent electron recoil excess observed by XENON1T has a possible interpretation in terms of solar axions coupled to electrons. If such axions are still relativistic at recombination they would also leave a cosmic imprint in the form of an additio
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::05f1e643364a20e7ca2682cfef4cf189
http://arxiv.org/abs/2007.06579
http://arxiv.org/abs/2007.06579
Autor:
Ricardo Z. Ferreira
Models of inflation where the entropic directions have large and negative masses $|m_s| \gg H$ can be well described by a single-field EFT with an imaginary sound speed $c_s$. Among other features, they predict an exponential enhancement of the spect
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::62d06a2fbd9a89352d2ab75290456f5d
Publikováno v:
Journal of Cosmology and Astroparticle Physics
Inflation can be supported in very steep potentials if it is generated by rapidly turning fields, which can be natural in negatively curved field spaces. The curvature perturbation, $\zeta$, of these models undergoes an exponential, transient amplifi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5f8966ffbff98a3a524a2cbdd3650162
http://arxiv.org/abs/1908.11316
http://arxiv.org/abs/1908.11316
Publikováno v:
Biblos-e Archivo. Repositorio Institucional de la UAM
Universidad Camilo José Cela (UCJC)
Universidad Camilo José Cela (UCJC)
Light axions can potentially leave a cosmic background, just like neutrinos. We complete the study of thermal axion production across the electroweak scale by providing a smooth and continuous treatment through the two phases. Focusing on both flavor
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::faecb438f5850c6de1fe1a2a6930f035
https://doi.org/10.1088/1475-7516/2021/03/090
https://doi.org/10.1088/1475-7516/2021/03/090
Publikováno v:
Physics of the Dark Universe. 26:100385
We consider a quintessence field which transitions from a matter-like to a cosmological constant behaviour between recombination and the present time. We aim at easing the tension in the measurement of the present Hubble rate, and we assess the Λ CD
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::27fd3bda5f1afca921e557a4fcce5b6f
https://doi.org/10.1016/j.dark.2019.100385
https://doi.org/10.1016/j.dark.2019.100385