Zobrazeno 1 - 10
of 13
pro vyhledávání: '"James Edholm"'
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 79, Iss 3, Pp 1-5 (2019)
Abstract It has been shown that the spectrum of quantum gravity contains at least two new modes in addition to the massless graviton: a massive spin-0 and a massive spin-2. We calculate their power spectrum during inflation and we argue that they cou
Externí odkaz:
https://doaj.org/article/4dcffc4e19264b6a8c82dd62fdbb462e
Autor:
James Edholm, Jonathan Pearson
Publikováno v:
Journal of High Energy Physics, Vol 2018, Iss 11, Pp 1-18 (2018)
Abstract We describe a new method to parameterise dark energy theories including massive gravity, elastic dark energy and tensor-metric theories. We first examine the existing framework which describes any second order Lagrangian which depends on the
Externí odkaz:
https://doaj.org/article/017b8504439c468182417f235192700f
Autor:
James Edholm, Masato Minamitsuji
Publikováno v:
Physical Review D. 101
We investigate static and spherically symmetric black hole (BH) solutions in shift-symmetric quadratic-order degenerate higher-order scalar-tensor (DHOST) theories. We allow a nonconstant kinetic term $X=g^{\mu\nu} \partial_\mu\phi\partial_\nu \phi$
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f6361a3277fc5d4348c3dc0a1d5c4db5
https://doi.org/10.1103/physrevd.101.044034
https://doi.org/10.1103/physrevd.101.044034
Autor:
Jonathan Pearson, James Edholm
Publikováno v:
Journal of High Energy Physics, Vol 2018, Iss 11, Pp 1-18 (2018)
Journal of high energy physics, 2018, Vol.2018(11), pp.180 [Peer Reviewed Journal]
Journal of High Energy Physics
Journal of high energy physics, 2018, Vol.2018(11), pp.180 [Peer Reviewed Journal]
Journal of High Energy Physics
We describe a new method to parameterise dark energy theories including massive gravity, elastic dark energy and tensor-metric theories. We first examine a framework to describe any second order Lagrangian which depends on the variation of the metric
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::16520e903a27f609777acaf52059250e
http://link.springer.com/article/10.1007/JHEP11(2018)180
http://link.springer.com/article/10.1007/JHEP11(2018)180
Autor:
James Edholm, Masato Minamitsuji
Publikováno v:
Physical Review D. 100
We show that most classes of shift-symmetric degenerate higher-order scalar-tensor (DHOST) theories which satisfy certain degeneracy conditions are not compatible with the conditions for the existence of exact black hole solutions with a linearly tim
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::747c768655575998b3e4c1206ca30d65
https://doi.org/10.1103/physrevd.100.044053
https://doi.org/10.1103/physrevd.100.044053
Autor:
James Edholm
Publikováno v:
Physical Review D. 97
Infinite Derivative Gravity is able to resolve the Big Bang curvature singularity present in general relativity by using a simplifying ansatz. We show that it can also avoid the Hawking- Penrose singularity, by allowing defocusing of null rays throug
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::43d123557d35a4b6af5b046b9a576162
https://doi.org/10.1103/physrevd.97.084046
https://doi.org/10.1103/physrevd.97.084046
Autor:
James Edholm
General Relativity is known to produce singularities in the potential generated by a point source. Our universe can be modelled as a de Sitter (dS) metric and we show that ghost-free Infinite Derivative Gravity (IDG) produces a non-singular potential
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::58e819e98231444ade25552eccb9bd10
https://doi.org/10.1103/PhysRevD.97.064011
https://doi.org/10.1103/PhysRevD.97.064011
Autor:
Aindriú Conroy, James Edholm
Recent study has shown that a non-singular oscillating potential, a feature of Infinite Derivative Gravity (IDG) theories, matches current experimental data better than the standard GR potential. In this work we show that this non-singular oscillatin
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a84d8207d2095027a0a1f4eb4d034298
http://arxiv.org/abs/1705.02382
http://arxiv.org/abs/1705.02382
Autor:
James Edholm
In this paper, we build upon the successes of the ultraviolet (UV) completion of the Starobinsky model of inflation. This involves an extension of the Einstein-Hilbert term by an infinite covariant derivative theory of gravity, which is quadratic in
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::aa75831e9c86d6eca591c14122702993
http://arxiv.org/abs/1611.05062
http://arxiv.org/abs/1611.05062
Publikováno v:
Journal of High Energy Physics. SPRINGER
ISSUE=8;ISSN=1029-8479;TITLE=Journal of High Energy Physics
Journal of High Energy Physics
ISSUE=8;ISSN=1029-8479;TITLE=Journal of High Energy Physics
Journal of High Energy Physics
In this paper we wish to find the corresponding Gibbons-Hawking-York term for the most general quadratic in curvature gravity by using Coframe slicing within the Arnowitt-Deser-Misner (ADM) decomposition of spacetime in four dimensions. In order to m
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0b937225629d6e6d8fa67594e9c7bcd4
https://research.rug.nl/en/publications/451c8834-ed04-4ef8-894e-7be57a2d94ad
https://research.rug.nl/en/publications/451c8834-ed04-4ef8-894e-7be57a2d94ad