Results 31 to 40 of about 197,098 (270)
Cosmological Constant Versus Quintessence [PDF]
International Journal of Theoretical Physics, 2000 There is some evidence that the Universe is presently undergoing accelerating expansion. This has restored some credit to the scenarios with a non-vanishing cosmological constant. From the point of view of a theory of fundamental interactions, one may argue that a dynamical component with negative pressure is easier to achieve.
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Scholarpedia, 2010 In the context of cosmology the cosmological constant is a homogeneous energy density that causes the expansion of the universe to accelerate. Originally proposed early in the development of general relativity in order to allow a static universe solution it was subsequently abandoned when the universe was found to be expanding.
Davis, Tamara, Griffen, Brendan
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Cosmological constant and time delay [PDF]
, 2008 The effect of the cosmological constant on the time delay caused by an isolated spherical mass is calculated without using the lens equation and compared to a recent observational bound on the time delay of the lensed quasar SDSS J1004+4112.Comment: 8 ...
Einstein +11 more
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Cosmological constant as a fundamental constant⋆ [PDF]
The European Physical Journal Plus, 2019 Eur Phys J Plus, to appear, 5 ...
Gurzadyan, V. G., Stepanian, A.
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Remarks on the Cosmological Constant [PDF]
, 2012 The acceleration of the surface of last scatter (SLS) must somehow reflect the energy content within it. A test particle at the SLS is assumed to experience a linear combination of two forces: one Newtonian, the other pseudo-Newtonian describable by a ...
Frampton, Paul H.
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The Quantum Cosmological Constant [PDF]
Symmetry, 2019 We present an extension of general relativity in which the cosmological constant becomes dynamical and turns out to be conjugate to the Chern–Simons invariant of the Ashtekar connection on a spatial slicing. The latter has been proposed Soo and Smolin as a time variable for quantum gravity: the Chern–Simons time.
Alexander, S, Magueijo, J, Smolin, L
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The Cosmological Constant is Back [PDF]
, 1995 A diverse set of observations now compellingly suggest that Universe possesses a nonzero cosmological constant. In the context of quantum-field theory a cosmological constant corresponds to the energy density of the vacuum, and the wanted value for the ...
B. Chaboyer +17 more
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Dynamical cosmological constant
Physical Review DThe dynamical realization of the equation of state p+ρ=0 is studied. A nonpathological dynamics for the perturbations of such a system mimicking a dynamical cosmological constant (DCC) requires to go beyond the perfect fluid paradigm. It is shown that an anisotropic stress must be always present. The Hamiltonian of the system in isolation resembles the
G. di Donato, L. Pilo
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Cosmological constant, violation of cosmological isotropy and CMB
, 2009 We suggest that the solution to the cosmological vacuum energy puzzle does not require any new field beyond the standard model, but rather can be explained as a result of the interaction of the infrared sector of the effective theory of gravity with ...
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Cosmological constant in spinfoam cosmology [PDF]
Physical Review D, 2011 4 pages, 2 ...
Bianchi, Eugenio +3 more
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