Results 111 to 120 of about 1,530,241 (273)

The simplicity of physical laws

Noûs, EarlyView.
Abstract Physical laws are strikingly simple, yet there is no a priori reason for them to be so. I propose that nomic realists—Humeans and non‐Humeans—should recognize simplicity as a fundamental epistemic guide for discovering and evaluating candidate physical laws.
Eddy Keming Chen
wiley   +1 more source

Some conceptual issues in loop quantum cosmology [PDF]

, 2016
Loop quantum gravity is a mature theory. To proceed to explicit calculations in cosmology, it is necessary to make assumptions and simplifications based on the symmetries of the cosmological setting. Symmetry reduction is especially critical when dealing
A. Barrau, B. Bolliet
semanticscholar   +1 more source

Quantum Cosmological Relational Model of Shape and Scale in 1-d

, 2011
Relational particle models are useful toy models for quantum cosmology and the problem of time in quantum general relativity. This paper shows how to extend existing work on concrete examples of relational particle models in 1-d to include a notion of ...
Abramowitz M, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E, Anderson E Barbour J B, Barbour J B, Barbour J B, Barbour J B, Barbour J B, Barbour J B, Barbour J B, Barbour J B Elze H-T, Barbour J B Foster B Z, Barbour J B Smolin L, Barvinsky A O, Barvinsky A O, Bojowald M, Courant R, Dirac P A M, Edward Anderson, Frose Fischer C, Gryb S B, Halliwell J J, Harrison E R, Hartle J B, Isham C J, Isham C J, Kiefer C, Kuchař K V, Kuchař K V, Kuchař K V, Kuchař K V, Kuchař K V Kunstatter G Vincent D Williams J, Lanczos C, Landau L D, Marchal C, Messiah A, Milne E A, Misner C W, Misner C W, Misner C W, Mizushima M, Moss I, Pauling L, Peebles P J E, Penrose R, Rindler W, Robinett R W, Rovelli C, Ryan M, Schwinger J, Smolin L, Smolin L, Tetradis N, Wheeler J A, Wilson A H, Wiltshire D L, Á Gergely L, Á Gergely L   +82 more
core   +1 more source

Lessons from the void: What Boltzmann brains teach

Analytic Philosophy, EarlyView.
Abstract Some physical theories predict that almost all brains in the universe are Boltzmann brains, that is, short‐lived disembodied brains that are accidentally assembled as a result of thermodynamic or quantum fluctuations. Physicists and philosophers of physics widely regard this proliferation as unacceptable, and so take its prediction as a basis ...
Bradford Saad
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, Ashtekar A., Ashtekar A., Bojowald M., Bojowald M., de Broglie L., F Shojai, Golshani M., Holland P. R., Pinto-Neto N., Prudnikov A. P., Rovelli C., Shojai A., Shojai A., Shojai F., Struyve W., Thiemann T.   +16 more
core   +1 more source

Loop cosmological dynamics and dualities with Randall-Sundrum braneworlds [PDF]

, 2006
The discrete quantum geometric effects play an important role in dynamical evolution in the loop quantum cosmology. These effects which are significant at the high energies lead to the quadratic energy density modifications to the Friedmann equation, as ...
A. Ashtekar, C. Rovelli, M. Bojowald, M. Sami, Parampreet Singh, R. Maartens, T. Thiemann   +6 more
core   +3 more sources

Quantum cosmological models [PDF]

Classical and Quantum Gravity, 2005
revised: now includes time asymmetry, black hole final state etc, 71 ...
openaire   +3 more sources

Chaos in Quantum Cosmology [PDF]

Physical Review Letters, 1998
Much of the foundational work on quantum cosmology employs a simple minisuperspace model describing a Friedmann-Robertson-Walker universe containing a massive scalar field. We show that the classical limit of this model exhibits deterministic chaos and explore some of the consequences for the quantum theory.
E. P. S. Shellard, Neil J. Cornish
openaire   +3 more sources

Spaceborne and spaceborn: Physiological aspects of pregnancy and birth during interplanetary flight

Experimental Physiology, EarlyView.
Abstract Crewed interplanetary return missions that are on the planning horizon will take years, more than enough time for initiation and completion of a pregnancy. Pregnancy is viewed as a sequence of processes – fertilization, blastocyst formation, implantation, gastrulation, placentation, organogenesis, gross morphogenesis, birth and neonatal ...
Arun V. Holden
wiley   +1 more source

An Overview on the Nature of the Bounce in LQC and PQM

Universe, 2021
We present a review on some of the basic aspects concerning quantum cosmology in the presence of cut-off physics as it has emerged in the literature during the last fifteen years.
Gabriele Barca, Eleonora Giovannetti, Giovanni Montani   +2 more
doaj   +1 more source