Results 81 to 90 of about 1,577,801 (299)
Primordial power spectra for scalar perturbations in loop quantum cosmology [PDF]
, 2016 We provide the power spectrum of small scalar perturbations propagating in an inflationary scenario within loop quantum cosmology. We consider the hybrid quantization approach applied to a Friedmann-Robertson-Walker spacetime with flat spatial sections ...
Daniel Martín de Blas, J. Olmedo
semanticscholar +1 more source
Time in quantum cosmology [PDF]
Physical Review D, 2016 A cosmological model with two global internal times shows that time reparameterization invariance, and therefore covariance, is not guaranteed by deparameterization.
M. Bojowald, Theodore Halnon
semanticscholar +1 more source
Quantum cosmological backreactions. II. Purely homogeneous quantum cosmology
Physical Review D, 2022 This is the second paper in a series of four in which we use space adiabatic methods in order to incorporate backreactions among the homogeneous and between the homogeneous and inhomogeneous degrees of freedom in quantum cosmological perturbation theory. The purpose of the present paper is twofold. On the one hand, it illustrates the formalism of space
J. Neuser, S. Schander, T. Thiemann
openaire +3 more sources
Reheating via gravitational particle production in simple models of quintessence or $\Lambda$CDM inflation [PDF]
, 2017 We have tested some simple $\Lambda$CDM (the same test is also valid for quintessence) inflation models, imposing that they match with the recent observational data provided by the BICEP and Planck's team and leading to a reheating temperature, which is ...
Haro, Jaume, Saló, Llibert Aresté
core +4 more sources
The DNA of Calabi–Yau Hypersurfaces
Fortschritte der Physik, EarlyView.Abstract Genetic Algorithms are implemented for triangulations of four‐dimensional reflexive polytopes, which induce Calabi–Yau threefold hypersurfaces via Batyrev's construction. These algorithms are shown to efficiently optimize physical observables such as axion decay constants or axion–photon couplings in string theory compactifications.
Nate MacFadden +2 more
wiley +1 more source
Causal Loop Quantum Gravity and Cosmological Solutions
, 2004 We shall present here the causal interpretation of canonical quantum gravity in terms of new variables. Then we shall apply it to the minisuperspace of cosmology.
A Shojai +16 more
core +1 more source
Real no-boundary wave function in Lorentzian quantum cosmology [PDF]
, 2017 It is shown that the standard no-boundary wave function has a natural expression in terms of a Lorentzian path integral with its contour defined by Picard-Lefschetz theory.
Juan Diaz Dorronsoro +4 more
semanticscholar +1 more source
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
openaire +4 more sources
Advanced Quantum Technologies, EarlyView.Quantum algorithms for differential equations are developed with applications in computational fluid dynamics. The methods follow an iterative simulation framework, implementing Jacobi and Gauss–Seidel schemes on quantum registers through linear combinations of unitaries.
Chelsea A. Williams +4 more
wiley +1 more source
Quantum out-of-equilibrium cosmology
European Physical Journal C: Particles and Fields, 2019 In this work, our prime focus is to study the one to one correspondence between the conduction phenomena in electrical wires with impurity and the scattering events responsible for particle production during stochastic inflation and reheating implemented
Sayantan Choudhury +3 more
doaj +1 more source