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pro vyhledávání: '"Barker, W"'
Autor:
Barker, W., Marzo, C.
In the context of weak-field metric-affine (i.e. Palatini) gravity near Minkowski spacetime, we compute the particle spectra in the simultaneous presence of all independent contractions quadratic in Ricci-type tensors. Apart from the full metric-affi
Externí odkaz:
http://arxiv.org/abs/2402.07641
The short answer is $\textit{probably no}$. Specifically, this paper considers a recent body of work which suggests that general relativity requires neither the support of dark matter halos, nor unconventional baryonic profiles, nor any infrared modi
Externí odkaz:
http://arxiv.org/abs/2303.11094
We investigate recent claims that gravitomagnetic effects in linearised general relativity can explain flat and rising rotation curves, such as those observed in galaxies, without the need for dark matter. If one models a galaxy as an axisymmetric, s
Externí odkaz:
http://arxiv.org/abs/2303.06115
Autor:
Rew, C., Barker, W. E. V.
Constant-torsion emergent gravity (CTEG) has a Lagrangian quadratic in curvature and torsion, but without any Einstein--Hilbert term. CTEG is motivated by a unitary, power-counting renormalisable particle spectrum. The timelike axial torsion adopts a
Externí odkaz:
http://arxiv.org/abs/2302.07250
Autor:
Barker, W. E. V.
Many theories of gravity are spoiled by strongly coupled modes: the high computational cost of Hamiltonian analysis can obstruct the identification of these modes. A computer algebra implementation of the Hamiltonian constraint algorithm for curvatur
Externí odkaz:
http://arxiv.org/abs/2206.00658
Autor:
Barker, W. E. V.
The dynamics of the torsion-powered teleparallel theory are only viable because thirty-six multiplier fields disable all components of the Riemann--Cartan curvature. We generalise this suggestive approach by considering Poincar\'e gauge theory in whi
Externí odkaz:
http://arxiv.org/abs/2205.13534
Publikováno v:
In Journal of Mathematical Analysis and Applications 15 September 2024 537(2)
Publikováno v:
Phys. Rev. D 104, 084036 (2021)
It was recently found that, when linearised in the absence of matter, 58 cases of the general gravitational theory with quadratic curvature and torsion are (i) free from ghosts and tachyons and (ii) power-counting renormalisable. We inspect the nonli
Externí odkaz:
http://arxiv.org/abs/2101.02645
Publikováno v:
Phys. Rev. D 102, 084002 (2020)
The ten-parameter, quadratic Poincar\'e gauge theory of gravity is a plausible alternative to general relativity. We show that the rich background cosmology of the gauge theory is described by a non-canonical bi-scalar-tensor theory in the Jordan fra
Externí odkaz:
http://arxiv.org/abs/2006.03581
Publikováno v:
Phys. Rev. D 102, 024048 (2020)
We propose a one-parameter extension to $\Lambda$CDM, expected to strongly affect cosmological tensions. An effective dark radiation component in the early universe redshifts away as hot dark matter, then quintessence, tracking the dominant equation-
Externí odkaz:
http://arxiv.org/abs/2003.02690