Zobrazeno 1 - 10
of 16
pro vyhledávání: '"Stéphane Fay"'
Autor:
Stéphane Fay
Publikováno v:
Monthly Notices of the Royal Astronomical Society
Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2020, 494 (2), pp.2183-2190. ⟨10.1093/mnras/staa940⟩
Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2020, 494 (2), pp.2183-2190. ⟨10.1093/mnras/staa940⟩
We examine the possibility that Universe expansion be made of some Λ-cold dark matter (ΛCDM) expansions repeating periodically, separated by some inflation- and radiation-dominated phases. This so-called ΛCDM periodic cosmology is motivated by the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::95c9a4e214ae3ff8dbb016d0cdea112d
https://doi.org/10.1093/mnras/staa940
https://doi.org/10.1093/mnras/staa940
Autor:
Stéphane FAYE
Publikováno v:
Akofena, Vol 04, Iss 013 (2024)
Résumé: Les Quaestiones convivales de l’écrivain, philosophe, moraliste et théologien Plutarque sont un terreau de réflexions certes éparses, mais utiles sur les animaux. Fictives ou avec une dose de réalité, les conversations y contenues n
Externí odkaz:
https://doaj.org/article/7f3e421cd4b34bb9aa676aa4735d6da3
Autor:
Stéphane Fay
The $\Lambda CDM$ expansion could be mimicked by a dark energy coupled to matter. Then, the equation of state $\bar w$ and coupling $\bar Q$ of this coupled dark energy could not be constrained by observations of the Hubble function alone. Also, in t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::55a20e30858b2784be4b3cfe27b210d8
http://arxiv.org/abs/1605.01644
http://arxiv.org/abs/1605.01644
Isotropization of Bianchi class A models with curvature for a minimally coupled scalar tensor theory
Autor:
Stéphane Fay
Publikováno v:
Classical and Quantum Gravity. 20:1363-1378
We look for necessary isotropisation conditions of Bianchi class $A$ models with curvature in presence of a massive and minimally coupled scalar field when a function $\ell$ of the scalar field tends to a constant, diverges monotonically or with suff
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f15aba11a70f733f17e9f56c98aa8ef4
https://doi.org/10.1088/0264-9381/20/7/308
https://doi.org/10.1088/0264-9381/20/7/308
Autor:
Stéphane Fay
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 426:1000-1002
Scalar–tensor theories are constrained with lunar laser ranging and supernova data at low redshift. This allows us to find some constraints on the scalar field independently of the form of its potential once the gravitation function is specified. W
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::83610e3ae16815703f4da2a960d7df28
https://doi.org/10.1111/j.1365-2966.2012.21562.x
https://doi.org/10.1111/j.1365-2966.2012.21562.x
Autor:
Stéphane Fay
Publikováno v:
Physical Review D
Physical Review D, American Physical Society, 2017, 95 (8), pp.083504. ⟨10.1103/PhysRevD.95.083504⟩
Phys.Rev.D
Phys.Rev.D, 2017, 95 (8), pp.083504. ⟨10.1103/PhysRevD.95.083504⟩
Phys.Rev.D, 2017, 95 (8), pp.083504. 〈10.1103/PhysRevD.95.083504〉
Physical Review D, American Physical Society, 2017, 95 (8), pp.083504. ⟨10.1103/PhysRevD.95.083504⟩
Phys.Rev.D
Phys.Rev.D, 2017, 95 (8), pp.083504. ⟨10.1103/PhysRevD.95.083504⟩
Phys.Rev.D, 2017, 95 (8), pp.083504. 〈10.1103/PhysRevD.95.083504〉
We consider a flat Universe filled with a vacuum energy coupled to matter and radiation by respectively positive coupling functions $Q_m$ and $Q_r$. We require that these functions be such as Universe exits from inflation to go to a radiation dominat
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1f4a3511ae354f9add8a51763eb579b8
Autor:
Stéphane Fay
Publikováno v:
Classical and Quantum Gravity. 19:269-278
We look for necessary conditions such that the minimally coupled scalar–tensor theory with a massive scalar field and a perfect fluid in the Bianchi type I model isotropizes. We then derive the dynamical asymptotical properties of the Universe.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::29da49b01b5431bafa18f522da62cba7
https://doi.org/10.1088/0264-9381/19/2/307
https://doi.org/10.1088/0264-9381/19/2/307
Autor:
Stéphane Fay
We consider General Relativity with matter and radiation, one of these fluids being coupled to vacuum. We find that Universe dynamics starts by an inflation phase if the coupled fluid has a negative energy density at early time. Then, there is always
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c0c67373a3cdea728279cda051f2be5f
http://arxiv.org/abs/1404.3518
http://arxiv.org/abs/1404.3518
Publikováno v:
Physical Review D. 76
We consider f(R) modified gravity theories in the metric variation formalism and attempt to reconstruct the function f(R) by demanding a background {lambda}CDM cosmology. In particular we impose the following requirements: (a) A background cosmic his
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::37d3f93216ba3b13cd64a3db301c3e79
https://doi.org/10.1103/physrevd.76.063504
https://doi.org/10.1103/physrevd.76.063504
Publikováno v:
Physical Review D. 75
We make a systematic study of the cosmological dynamics for a number of f(R) gravity theories in Palatini formalism, using phase space analysis as well as numerical simulations. Considering homogeneous and isotropic models, we find a number of intere
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3e2084db93a4a62d1b65575303bc7935
https://doi.org/10.1103/physrevd.75.063509
https://doi.org/10.1103/physrevd.75.063509