Zobrazeno 1 - 10
of 31
pro vyhledávání: '"João Marto"'
Autor:
K. Sravan Kumar, João Marto
Publikováno v:
Universe, Vol 10, Iss 8, p 320 (2024)
Quantum field theory (QFT) in Rindler spacetime is a gateway to understanding unitarity and information loss paradoxes in curved spacetime. Rindler coordinates map Minkowski spacetime onto regions with horizons, effectively dividing accelerated obser
Externí odkaz:
https://doaj.org/article/2d34aa420861474490323ec19b4c2d74
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 81, Iss 9, Pp 1-13 (2021)
Abstract We analyse the phenomenological effects of a varying Dark Energy (DE) effective speed of sound parameter, $$c^{2}_{\text {sd}}$$ c sd 2 , on the cosmological perturbations of three phantom DE models. Each of these models induce a particular
Externí odkaz:
https://doaj.org/article/1ffc91dba6284bbfa2c9bba9c0f6451a
Autor:
João Marto
Publikováno v:
Universe, Vol 7, Iss 8, p 297 (2021)
The purpose of this paper is to analyse the back reaction problem, between Hawking radiation and the black hole, in a simplified model for the black hole evaporation in the quantum geometrodynamics context. The idea is to transcribe the most importan
Externí odkaz:
https://doaj.org/article/0414c2d894a54ae1ad9602470c6751f5
Publikováno v:
Universe, Vol 3, Iss 1, p 21 (2017)
The latest cosmological observations by the Planck collaboration (and combined with others) are compatible with a phantom-like behaviour ( w < − 1 ) for the dark energy equation of state that drives the current acceleration of the Universe. With th
Externí odkaz:
https://doaj.org/article/6651295aa6864e048e8686036e91f4cf
Autor:
Marta Machado-Pereira, Alba Grayston, Miguel Garcia-Gabilondo, Vitor Francisco, Ana Cristóvão, João Marto, Helena Vieira, Miguel Viana-Baptista, Lino Ferreira, Liliana Bernardino, Anna Rosell, Raquel Ferreira
Publikováno v:
Stroke. 54
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::cc68d32ce4fe4c871c998858918923c5
https://doi.org/10.1161/strokeaha.122.041839
https://doi.org/10.1161/strokeaha.122.041839
Publikováno v:
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Agência para a Sociedade do Conhecimento (UMIC)-FCT-Sociedade da Informação
instacron:RCAAP
Journal of Cosmology and Astroparticle Physics, 2019(2):020. IOP PUBLISHING LTD
Agência para a Sociedade do Conhecimento (UMIC)-FCT-Sociedade da Informação
instacron:RCAAP
Journal of Cosmology and Astroparticle Physics, 2019(2):020. IOP PUBLISHING LTD
In this paper, we will show that the equations of motion of the quadratic in curvature, ghost free, infinite derivative theory of gravity will not permit an anisotropic collapse of a homogeneous Universe such as Kasner-type vacuum solution. However,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ef1d4f88c00dd69803d17178cb7b2a9a
https://research.rug.nl/en/publications/d5173e91-7143-4bca-ae40-f390d6f4e749
https://research.rug.nl/en/publications/d5173e91-7143-4bca-ae40-f390d6f4e749
Publikováno v:
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Agência para a Sociedade do Conhecimento (UMIC)-FCT-Sociedade da Informação
instacron:RCAAP
Agência para a Sociedade do Conhecimento (UMIC)-FCT-Sociedade da Informação
instacron:RCAAP
In this paper, by establishing a Brans-Dicke (BD) cosmology by means of a deformed phase space, in the absence of any scalar potential, cosmological constant and ordinary matter, we show that it is feasible to overcome obstacles reported in the corre
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9713eaae82f9950aa0f13748f8fe5006
Autor:
Gerhard Harmsen, Anupam Mazumdar, João Marto, Alan S. Cornell, Alexey S. Koshelev, Gaetano Lambiase, Luca Buoninfante
Publikováno v:
Physical Review D, 98(8):084041. AMER PHYSICAL SOC
The vacuum solution of Einstein's theory of general relativity provides a rotating metric with a ring singularity, which is covered by the inner and outer horizons, and an ergo region. In this paper, we will discuss how ghost-free, quadratic curvatur
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b9a43bbce5cfb5da10e581b23321c358
https://doi.org/10.1103/physrevd.98.084041
https://doi.org/10.1103/physrevd.98.084041
Publikováno v:
Journal of Cosmology and Astroparticle Physics. IOP PUBLISHING LTD
ISSUE=6;ISSN=1475-7516;TITLE=Journal of Cosmology and Astroparticle Physics
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Agência para a Sociedade do Conhecimento (UMIC)-FCT-Sociedade da Informação
instacron:RCAAP
ISSUE=6;ISSN=1475-7516;TITLE=Journal of Cosmology and Astroparticle Physics
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Agência para a Sociedade do Conhecimento (UMIC)-FCT-Sociedade da Informação
instacron:RCAAP
In Einstein's theory of general relativity the vacuum solution yields a blackhole with a curvature singularity, where there exists a point-like source with a Dirac delta distribution which is introduced as a boundary condition in the static case. It
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1227374b0c1f3a3ad4fb83f3a05ca19a
https://research.rug.nl/en/publications/5dd51fdd-995a-4bda-ab8d-b8c5bd76d517
https://research.rug.nl/en/publications/5dd51fdd-995a-4bda-ab8d-b8c5bd76d517
Publikováno v:
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Agência para a Sociedade do Conhecimento (UMIC)-FCT-Sociedade da Informação
instacron:RCAAP
Agência para a Sociedade do Conhecimento (UMIC)-FCT-Sociedade da Informação
instacron:RCAAP
We consider a noncommutative (NC) inflationary model with a homogeneous scalar field minimally coupled to gravity. The particular NC inflationary setting produces entirely new consequences. We first analyze the free field case and subsequently examin
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::72e5d66e612d5989ed931c2786b2f381