Zobrazeno 1 - 10
of 363
pro vyhledávání: '"C.J.A.P. Martins"'
Publikováno v:
Physics Letters B, Vol 855, Iss , Pp 138788- (2024)
Cosmic string networks are expected to form in early Universe phase transitions via the Kibble mechanism and are unavoidable in several Beyond the Standard Model theories. While most predictions of observational signals of string networks assume feat
Externí odkaz:
https://doaj.org/article/75b999aba120490b8e17a09c3200cdb6
Publikováno v:
Physics Letters B, Vol 835, Iss , Pp 137570- (2022)
The cosmic microwave background temperature is a cornerstone astrophysical observable. Its present value is tightly constrained, but its redshift dependence, which can now be determined until redshift z∼6.34, is also an important probe of fundament
Externí odkaz:
https://doaj.org/article/aa6ba2082cbe40d09326ca2498addf23
Publikováno v:
Physics Letters B, Vol 827, Iss , Pp 137002- (2022)
Cosmography is a phenomenological and relatively model-independent approach to cosmology, where physical quantities are expanded as a Taylor series in the cosmological redshift, or in related variables. Here we apply this methodology to constrain pos
Externí odkaz:
https://doaj.org/article/b1ca6f7fc818472c8f00355d2e913e5e
Autor:
C.J.A.P. Martins, M. Prat Colomer
Publikováno v:
Physics Letters B, Vol 791, Iss , Pp 230-235 (2019)
We use recent astrophysical and local tests of the stability of the fine-structure constant, α, to constrain a particular phenomenological but physically motivated class of models in which the dark energy equation of state can undergo a rapid transi
Externí odkaz:
https://doaj.org/article/b8aa84ae83eb40e18fcb3721a044af20
Autor:
C.J.A.P. Martins
Publikováno v:
Physics Letters B, Vol 788, Iss , Pp 147-151 (2019)
There has been recent interest in the evolution and cosmological consequences of global axionic string networks, and in particular in the issue of whether or not these networks reach the scale-invariant scaling solution that is known to exist for the
Externí odkaz:
https://doaj.org/article/65a478874c3d47dc99afd5872312ff1c
Publikováno v:
Physics Letters B, Vol 770, Iss C, Pp 93-100 (2017)
We use Fisher Matrix analysis techniques to forecast the cosmological impact of astrophysical tests of the stability of the fine-structure constant to be carried out by the forthcoming ESPRESSO spectrograph at the VLT (due for commissioning in late 2
Externí odkaz:
https://doaj.org/article/1fc2d922c46047aea82d435fb391b567
Publikováno v:
Physics Letters B, Vol 769, Iss C, Pp 491-497 (2017)
We introduce a methodology to test models with spatial variations of the fine-structure constant α, based on the calculation of the angular power spectrum of these measurements. This methodology enables comparisons of observations and theoretical mo
Externí odkaz:
https://doaj.org/article/54446e0092b84edba35bff26ff14f77d
Autor:
A.M.M. Pinho, C.J.A.P. Martins
Publikováno v:
Physics Letters B, Vol 756, Iss C, Pp 121-125 (2016)
Recent work by Webb et al. has provided indications of spatial variations of the fine-structure constant, α, at a level of a few parts per million. Using a dataset of 293 archival measurements, they further show that a dipole provides a statisticall
Externí odkaz:
https://doaj.org/article/3ccca1b230f74e8a8caa1b0e23392686
Publikováno v:
Physics Letters B, Vol 749, Iss C, Pp 389-392 (2015)
Astrophysical tests of the stability of Nature's fundamental couplings are a key probe of the standard paradigms in fundamental physics and cosmology. In this report we discuss updated constraints on the stability of the fine-structure constant α an
Externí odkaz:
https://doaj.org/article/e2c8a0394fbc44b9a2798956b257f6e0
Publikováno v:
Physics Letters B, Vol 747, Iss C, Pp 426-432 (2015)
We use three domain wall simulations from the radiation era to the late-time dark energy domination era based on the PRS algorithm to calculate the energy–momentum tensor components of domain wall networks in an expanding universe. Unequal time cor
Externí odkaz:
https://doaj.org/article/684e829e98af4d708b6957eaf4a4a71b