Results 61 to 70 of about 39,698 (245)
Effective Field Theory of Loop Quantum Cosmology
Universe, 2019 Quantum cosmology is traditionally formulated in a minisuperspace setting, implicitly averaging fields over space to obtain homogeneous models. For universal reasons related to the uncertainty principle, quantum corrections then depend on the size of the
Martin Bojowald
doaj +1 more source
Phenomenological implications of an alternative Hamiltonian constraint for quantum cosmology
, 2005 In this paper we review a model based on loop quantum cosmology that arises from a symmetry reduction of the self dual Plebanski action. In this formulation the symmetry reduction leads to a very simple Hamiltonian constraint that can be quantized ...
A. Ashtekar +6 more
core +1 more source
Loop Quantum Cosmology from Loop Quantum Gravity
EPL (Europhysics Letters), 2014 We show how Loop Quantum Cosmology can be derived as an effective semiclassical description of Loop Quantum Gravity. Using the tools of QRLG, a gauge fixed version of LQG, we take the coherent states of the fundamental microscopic theory suitable to describe a Bianchi I Universe and we find a mapping between the expectation value of the Hamiltonian and
Alesci, Emanuele, Cianfrani, Francesco
openaire +4 more sources
Inflationary Cosmology and Quantization Ambiguities in Semi-Classical Loop Quantum Gravity [PDF]
, 2004 In loop quantum gravity, modifications to the geometrical density cause a self-interacting scalar field to accelerate away from a minimum of its potential.
A. Ashtekar +30 more
core +3 more sources
Symmetry Reduction of Loop Quantum Gravity
, 2011 The relation between standard Loop Quantum Cosmology and full Loop Quantum Gravity fails already at the first nontrivial step: The configuration space of Loop Quantum Cosmology can not be embedded into the configuration space of full Loop Quantum Gravity
Brunnemann, Johannes, Koslowski, Tim A.
core +1 more source
Quantum Nature of the Big Bang: Improved dynamics [PDF]
, 2006 An improved Hamiltonian constraint operator is introduced in loop quantum cosmology. Quantum dynamics of the spatially flat, isotropic model with a massless scalar field is then studied in detail using analytical and numerical methods.
A. Ashtekar +11 more
core +3 more sources
Phantasmic Encounters in the Arctic: Haunting Materialities Beyond the Ghosts of War
Anthropology of Consciousness, EarlyView.ABSTRACT In the vast north, ghostly experiences are common for locals and outsiders alike. Here, we explore how cultural‐natural attributes, like remoteness and extreme seasonal variation, compound experiences of the haunting in visceral ways. This provides the Arctic region with an unusually pronounced baseline of other‐than‐human agency, which in the
Aki Hakonen, Oula Seitsonen
wiley +1 more source
Frontiers in Astronomy and Space Sciences, 2021 While the standard, six-parameter, spatially flat ΛCDM model has been highly successful, certain anomalies in the cosmic microwave background bring out a tension between this model and observations.
Abhay Ashtekar +3 more
doaj +1 more source
Observational Exclusion of a Consistent Quantum Cosmology Scenario
, 2015 It is often argued that inflation erases all the information about what took place before it started. Quantum gravity, relevant in the Planck era, seems therefore mostly impossible to probe with cosmological observations.
Barrau, Aurelien +3 more
core +3 more sources
Modern Theology, EarlyView.Abstract This essay, designed as a complement to opinions expressed by Rowan Williams and some speakers at the conference in his honour, explores features of early Christianity which suggest a positive evaluation of artificial intelligence. Noting that the fear of reducing humans to machines has been joined in the modern age by the fear that machines ...
Mark J. Edwards
wiley +1 more source