Results 11 to 20 of about 299,841 (224)
Non-linear isocurvature perturbations and non-Gaussianities [PDF]
, 2008 24 pagesWe study non-linear primordial adiabatic and isocurvature perturbations and their non-Gaussianity. After giving a general formulation in the context of an extended $\delta N$ formalism, we analyse in detail two illustrative examples. The first is
Vernizzi, F. +4 more
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Applications of cosmological perturbation theory [PDF]
, 2011 PhDCosmological perturbation theory is crucial for our understanding of the universe. The linear theory has been well understood for some time, however developing and applying the theory beyond linear order is currently at the forefront of research in
Christopherson, Adam J.
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Cosmological perturbations in antigravity [PDF]
Physical Review D, 2014 15 pages, a few references ...
Oltean, Marius, Brandenberger, Robert
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Constraining inflationary scenarios with braneworld models and second order cosmological perturbations [PDF]
, 2010 PhDInflationary cosmology is the leading explanation of the very early universe. Many different models of inflation have been constructed which fit current observational data.
Huston, Ian
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On cosmological perturbations of quasidilaton [PDF]
Classical and Quantum Gravity, 2013 A theory of the quasidilaton is an extension of massive gravity by a scalar field, nonlinearly realizing a certain new global symmetry of the Lagrangian. It has been shown that unlike pure massive gravity, this theory does admit homogeneous and isotropic spatially flat solutions.
D'Amico, Guido +3 more
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Scalar cosmological perturbations [PDF]
Classical and Quantum Gravity, 2012 Scalar perturbations of Friedmann-Lemaitre cosmologies can be analyzed in a variety of ways using Einstein's field equations, the Ricci and Bianchi identities, or the conservation equations for the stress-energy tensor, and possibly introducing a timelike reference congruence.
Uggla, Claes, Wainwright, John
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Linear cosmological perturbations in scalar-tensor-vector gravity
Physics Letters B, 2020 We investigate the cosmological perturbations in the context of a Scalar-Tensor-Vector theory of Gravity known as MOG in the literature. Recent investigations show that MOG reproduces a viable background cosmological evolution comparable to ΛCDM. However,
Sara Jamali +2 more
doaj +1 more source
Matching conditions for cosmological perturbations [PDF]
Physical Review D, 1995 We derive the matching conditions for cosmological perturbations in a Friedmann Universe where the equation of state undergoes a sharp jump, for instance as a result of a phase transition. The physics of the transition which is needed to follow the fate of the perturbations is clarified.
Deruelle, Nathalie, Mukhanov, V. F.
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COSMOLOGICAL PERTURBATIONS IN RENORMALIZATION GROUP DERIVED COSMOLOGIES [PDF]
International Journal of Modern Physics D, 2004 A linear cosmological perturbation theory of an almost homogeneous and isotropic perfect fluid Universe with dynamically evolving Newton constant G and cosmological constant Λ is presented. A gauge invariant formalism is developed by means of the covariant approach, and the acoustic propagation equations governing the evolution of the comoving ...
Bonanno, A., Reuter, M.
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The dynamics of cosmological scenarios inspired by quantum gravity [PDF]
, 2006 PhDIn this thesis we study the dynamics of cosmological scenarios inspired by quantum gravity. Part I investigates novel features of the semi-classical regime of homogeneous and isotropic loop quantum cosmology.
Mulryne, David James
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