Results 91 to 100 of about 1,973 (175)
Gravitational Fluctuations as an Alternative to Inflation
Universe, 2019 The ability to reproduce the observed matter power spectrum P ( k ) to high accuracy is often considered as a triumph of inflation. In this work, we explore an alternative explanation for the power spectrum based on nonperturbative quantum field ...
Herbert W. Hamber
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Isaacson expansion in quantum cosmology [PDF]
Physical Review D, 1993 This paper is an application of the ideas of the Born-Oppenheimer (or slow/fast) approximation in molecular physics and of the Isaacson (or short-wave) approximation in classical gravity to the canonical quantization of a perturbed minisuperspace model of the kind examined by Halliwell and Hawking.
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Gravitational Fluctuations as an Alternative to Inflation II. CMB Angular Power Spectrum
Universe, 2019 Power spectra always play an important role in the theory of inflation. In particular, the ability to reproduce the galaxy matter power spectrum P ( k ) and the CMB temperature angular power spectrum C l ’s to high accuracy is often ...
Herbert W. Hamber, Lu Heng Sunny Yu
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Higher-derivative Quantum Cosmology [PDF]
General Relativity and Gravitation, 2000 The quantum cosmology of a higher-derivative derivative gravity theory arising from the heterotic string effective action is reviewed. A new type of Wheeler-DeWitt equation is obtained when the dilaton is coupled to the quadratic curvature terms. Techniques for solving the Wheeler-DeWitt equation with appropriate boundary conditions shall be described,
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Starobinsky potential and power suppression in hybrid loop quantum cosmology
Physics Letters BWe study the effect on the primordial tensor power spectrum of varying the number of e-folds during slow-roll inflation in Loop Quantum Cosmology with a Starobinsky potential. Using the hybrid quantization approach, we derive the effective mass governing
Marceau Henry +2 more
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Pensamiento. Revista de Investigación e Información Filosófica, 2013 So far we can identify at least three concepts within modern cosmology that bring into debate the question of consciousness in the universe: 1) Fine Tuning; 2) The Anthropic Principle and 3) The Multiverse.
Khalil Chamcham
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On the cosmological constant in quantum cosmology
, 2006 This paper was published originally in "Problems of Gravitational Theory and Particle Theory", VNIIFTRI Proceedings, Moscow, 1972. v. 16(46), pp. 43-48 (in Russian).
Kalinin M.I., Melnikov V.N.
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Quantum Einsteinian cubic cosmology
European Physical Journal C: Particles and FieldsWe study Cosmological Einsteinian Cubic Gravity (CECG) in the context of minisuperspace quantum cosmology. CECG is a modification of Einstein’s gravity by cubic curvature terms that contribute non-trivially to the dynamics of FRW backgrounds, while the ...
Nephtalí Eliceo Martínez Pérez +1 more
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Journal of Cosmology and Astroparticle PhysicsAbstract This work applies the principles of quantum cosmology to examine models incorporating a quintom field. Specifically, three distinct models are analyzed: a simplified toy model, a model featuring an exponential quintom potential, and one where the quintom field is coupled with a negative cosmological constant. For each case,
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, 2001 A simple and surprisingly realistic model of the origin of the universe can be developed using the Friedmann equation from general relativity, elementary quantum mechanics, and the experimental values of h, c, G and the proton mass. The model assumes there are N space dimensions (with N > 6) and the potential constraining the radius r of the ...
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