Zobrazeno 1 - 10
of 263
pro vyhledávání: '"Peter, Patrick"'
Publikováno v:
Phys. Rev. D 110, 043512 (2024)
We propose a new method to investigate signatures of a quantum gravity phase in the primordial state of cosmological perturbations. We formulate and study a quantum model of a perturbed Friedmann-Lemaitre-Robertson-Walker universe beyond a tensor-pro
Externí odkaz:
http://arxiv.org/abs/2405.09307
Primordial black holes (PBHs) are hypothetical objects that could have originated from density fluctuations in a very early phase of our Universe. Recent observations restrict the masses that such PBHs could have, if they are to constitute all of dar
Externí odkaz:
http://arxiv.org/abs/2405.08113
We continue our studies of the evolution and cosmological consequences of current-carrying cosmic string networks, described by a charge-velocity-dependent one scale (CVOS) model. We present a detailed calculation of the effects of these networks on
Externí odkaz:
http://arxiv.org/abs/2403.16332
Publikováno v:
Phys.Rev.D 109 (2024) 10, 106005
We study the non-unitary relation between quantum gravitational models defined using different internal times. We show that despite the non-unitarity, it is possible to provide a prescription for making unambiguous, though restricted, physical predic
Externí odkaz:
http://arxiv.org/abs/2401.06887
Publikováno v:
Phys. Rev. D 109, 023516 (2024)
We have discovered a class of dynamically stable coherent states for motion on the half-line. The regularization of the half-line boundary and the consequent quantum motion are expounded within the framework of covariant affine quantization, although
Externí odkaz:
http://arxiv.org/abs/2310.16868
We consider the evolution of current-carrying cosmic string networks described by the charge-velocity-dependent one scale (CVOS) model beyond the linear equation of state regime, specifically focusing on the Witten superconducting model. We find that
Externí odkaz:
http://arxiv.org/abs/2304.00053
Publikováno v:
Phys.Rev.D 109 (2024) 6, 066009
A quantum cosmological bouncing model may exhibit an ambiguity stemming from the nonclassical nature of the background evolution: two classically equivalent theories can produce two qualitatively different potentials sourcing the perturbations. We de
Externí odkaz:
http://arxiv.org/abs/2212.12484
Autor:
Micheli, Amaury, Peter, Patrick
General relativity and its cosmological solution predicts the existence of tensor modes of perturbations evolving on top of our Friedman-Lema\^itre-Robertson-Walker expanding Universe. Being gauge invariant and not necessarily coupled to other quantu
Externí odkaz:
http://arxiv.org/abs/2211.00182
We consider a simple cosmological model consisting of an empty Bianchi I Universe, whose Hamiltonian we deparametrise to provide a natural clock variable. The model thus effectively describes an isotropic universe with an induced clock given by the s
Externí odkaz:
http://arxiv.org/abs/2201.09138
Autor:
Kiefer, Claus, Peter, Patrick
Publikováno v:
Universe 2022, 8, 36
Time in quantum gravity is not a well-defined notion, despite its central role in the very definition of dynamics. Using the formalism of quantum geometrodynamics, we shortly review the problem and illustrate it with two proposed solutions. Our main
Externí odkaz:
http://arxiv.org/abs/2112.05788