Results 111 to 120 of about 116,432 (201)
New ekpyrotic quantum cosmology
Physics Letters B, 2015 Ekpyrotic instantons describe the emergence of classical contracting universes out of the no-boundary quantum state. However, up to now these instantons ended in a big crunch singularity.
Jean-Luc Lehners
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General covariant transition amplitudes in quantum cosmology
, 2011 The path-integral approach to cosmology consists in the computation of transition amplitudes between states of the quantum geometry of the universe.
Vidotto, Francesca
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Within the framework of the new formalism of quantum theory - the quantum principle of least action - the initial state of the universe is determined, which is an analogue of the Hartle-Hawking no-boundary wave function. The quantum evolution of the universe is modified by additional conditions in a certain compact region of space-time, which is called
Natalia Gorobey +2 more
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A QUANTUM APPROACH TO COSMOLOGY [PDF]
, 2006 We present a theory based upon the treatment of the gravitational field as a sea of gravity quanta, as defined elsewhere. The resultant model for the Universe is a static one, like Einstein first saw, with a new feature: a local shrinking quantum world that completely explains the Hubble red shift under a new point of view.
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Reports in Advances of Physical SciencesThis paper aims to demonstrate that modern cosmology has overlooked the systematic and holistic aspects of the universe’s evolution. It is based on the notion that the primordial universe comprised a two-component quantum superfluid and a synthesis of ...
Xiaodong Yang +3 more
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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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Quantum Cosmology in the Light of Quantum Mechanics [PDF]
Galaxies, 2019 There is a formal analogy between the evolution of the universe, when this is seen as a trajectory in the minisuperspace, and the worldline followed by a test particle in a curved spacetime. The analogy can be extended to the quantum realm, where the trajectories are transformed into wave packets that give us the probability of finding the universe or ...
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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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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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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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