Zobrazeno 1 - 10
of 266
pro vyhledávání: '"Dubovsky, S."'
Publikováno v:
Phys. Rev. D 88, 117701 (2013)
We revisit cosmic microwave background (CMB) constraints on the abundance of millicharged particles based on the Planck data. The stringent limit Omega_{mcp}h^2 < 0.001 (95% CL) may be set using the CMB data alone if millicharged particles participat
Externí odkaz:
http://arxiv.org/abs/1310.2376
We explore the cosmological solutions of a recently proposed extension of General Relativity with a Lorentz-invariant mass term. We show that the same constraint that removes the Boulware-Deser ghost in this theory also prohibits the existence of hom
Externí odkaz:
http://arxiv.org/abs/1108.5231
Autor:
Dubovsky, S. L., Sibiryakov, S. M.
Publikováno v:
Phys.Lett.B638:509-514,2006
We study the effect of spontaneous breaking of Lorentz invariance on black hole thermodynamics. We consider a scenario where Lorentz symmetry breaking manifests itself by the difference of maximal velocities attainable by particles of different speci
Externí odkaz:
http://arxiv.org/abs/hep-th/0603158
Publikováno v:
JHEP0603:025,2006
We study whether a violation of the null energy condition necessarily implies the presence of instabilities. We prove that this is the case in a large class of situations, including isotropic solids and fluids relevant for cosmology. On the other han
Externí odkaz:
http://arxiv.org/abs/hep-th/0512260
Publikováno v:
Phys.Rev. D72 (2005) 084011
We study Lorentz-violating models of massive gravity which preserve rotations and are invariant under time-dependent shifts of the spatial coordinates. In the linear approximation the Newtonian potential in these models has an extra ``confining'' ter
Externí odkaz:
http://arxiv.org/abs/hep-th/0504067
Publikováno v:
Phys.Rev.Lett. 94 (2005) 181102
We construct a consistent model of gravity where the tensor graviton mode is massive, while linearized equations for scalar and vector metric perturbations are not modified. The Friedmann equation acquires an extra dark-energy component leading to ac
Externí odkaz:
http://arxiv.org/abs/hep-th/0411158
Autor:
Dubovsky, S. L.
Publikováno v:
JHEP0410:076,2004
We systematically study the most general Lorentz-violating graviton mass invariant under three-dimensional Eucledian group using the explicitly covariant language. We find that at general values of mass parameters the massive graviton has six propaga
Externí odkaz:
http://arxiv.org/abs/hep-th/0409124
Autor:
Dubovsky, S. L.
Publikováno v:
JCAP 0407 (2004) 009
We consider the infrared modification of gravity by ghost condensate. Naively, in this scenario one expects sizeable modification of gravity at distances of order 1000 km, provided that the characteristic time scale of the theory is of the order of t
Externí odkaz:
http://arxiv.org/abs/hep-ph/0403308
Autor:
Dubovsky, S. L., Sibiryakov, S. M.
Publikováno v:
Nucl.Phys. B691 (2004) 91-110
Noncommutative U(N) gauge theories at different N may be often thought of as different sectors of a single theory. For instance, U(1) theory possesses a sequence of vacua labeled by an integer parameter N, and the theory in the vicinity of the N-th v
Externí odkaz:
http://arxiv.org/abs/hep-th/0401046
Publikováno v:
JETP Lett. 79 (2004) 1-5; Pisma Zh.Eksp.Teor.Fiz. 79 (2004) 3-7
We calculate the cosmic microwave background (CMB) anisotropy spectrum in models with millicharged particles of electric charge q\sim 10^{-6}-10^{-1} in units of electron charge. We find that a large region of the parameter space for the millicharged
Externí odkaz:
http://arxiv.org/abs/hep-ph/0311189