Results 11 to 20 of about 1,973 (175)
Quantum String Cosmology [PDF]
Universe, 2021 We present a short review of possible applications of the Wheeler-De Witt equation to cosmological models based on the low-energy string effective action, and characterised by an initial regime of asymptotically flat, low energy, weak coupling evolution.
Maurizio Gasperini
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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.
Stephon Alexander +2 more
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DECOHERENCE IN QUANTUM COSMOLOGY AND THE COSMOLOGICAL CONSTANT [PDF]
Modern Physics Letters A, 2013 We discuss a spacetime having the topology of S3×ℝ but with a different smoothness structure. The initial state of the cosmos in our model is identified with a wildly embedded 3-sphere (or a fractal space). In previous work we showed that a wild embedding is obtained by a quantization of a usual (or tame) embedding.
Asselmeyer-Maluga, T., Krol, J.
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Lorentzian quantum cosmology [PDF]
Physical Review D, 2017 We argue that the Lorentzian path integral is a better starting point for quantum cosmology than the Euclidean version. In particular, we revisit the mini-superspace calculation of the Feynman path integral for quantum gravity with a positive cosmological constant. Instead of rotating to Euclidean time, we deform the contour of integration over metrics
Feldbrugge, Job +2 more
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Is a loopy and noncommutative early Universe viable?
Physics Letters B, 2023 We conduct a (pre-)inflationary dynamics study of the chaotic quadratic potential within the framework of a simple noncommutative extension of effective loop quantum cosmology put forward recently.
Luis Rey Díaz-Barrón +3 more
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Universe, 2021 The goal of this contribution is to present the properties of a class of quantum bouncing models in which the quantum bounce originates from the Dirac canonical quantization of a midi-superspace model composed of a homogeneous and isotropic background ...
Nelson Pinto-Neto
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Modern cosmology: 100 years of quantum science [PDF]
Kragujevac Journal of ScienceIn this article, we contribute to the special issue of the Kragujevac Journal of Science devoted to the International Year of Quantum Science and Technology (IYQ2025). We discuss several connections between Quantum Theory and Modern Cosmology.
Dimitrijević Dragoljub D. +1 more
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L'emergenza dello spazio-tempo nella gravità quantistica e nella cosmologia quantistica
Philosophy Kitchen, 2019 Our best description of spacetime is provided by general relativity – yet, this theory is not thought to be fundamental. Instead, it is expected to be replaced by a theory of quantum gravity, which may not feature spacetime fundamentally.
Karen Crowther
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(b,v)-type variables for black to white hole transitions in effective loop quantum gravity
Physics Letters B, 2021 Quantum gravity effects in effective models of loop quantum gravity, such as loop quantum cosmology, are encoded in the choice of so-called polymerisation schemes.
Norbert Bodendorfer +2 more
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