Results 71 to 80 of about 2,756,107 (244)

A short pre-history of Quantum Gravity [PDF]

, 2022
I describe the early, from the nineteen sixties, history of attempts at quantizing General Relativity.
arxiv   +1 more source

Simple quantum cosmology: Vacuum energy and initial state

, 2005
A static non-singular 10-dimensional closed Friedmann universe of Planck size, filled with a perfect fluid with an equation of state with w = -2/3, can arise spontaneously by a quantum fluctuation from nothing in 11-dimensional spacetime.
D. Spergel, D. Youm, E. Elbaz, M. Novello, M. Tegmark, S. Alexander, S. Eidelman, T. R. Mongan, T.R. Mongan   +8 more
core   +2 more sources

Identification of Ti(salen)‐Complexes for Efficient Catalysis in Single Electron Steps by Cyclic Voltammetry (CV)

Angewandte Chemie International Edition, Accepted Article.
We describe the identification of an active Ti(salen)‐catalyst for the radical arylation of epoxides by a CV study of mechanism‐based predictors, such as the redox potentials of the complexes and their EqCr‐equilibria, for the success of catalysis. Surprisingly, the by far most active catalyst features an uncommon tetrasubstituted ligand backbone that ...
Andreas Gansäuer, Niklas Schmickler, Sergei Gerber, Lennart Hanz, Stefan Grimme, Zheng-Wang Qu, Inke Siewert   +6 more
wiley   +1 more source

Comparison of primordial tensor power spectra from the deformed algebra and dressed metric approaches in loop quantum cosmology

, 2015
Loop quantum cosmology tries to capture the main ideas of loop quantum gravity and to apply them to the Universe as a whole. Two main approaches within this framework have been considered to date for the study of cosmological perturbations: the dressed ...
Barrau, A., Bolliet, B., Grain, J., Linsefors, L., Stahl, C.   +4 more
core   +3 more sources

The 1919 measurement of the deflection of light [PDF]

, 2014
The measurement of the deflection of starlight during a total solar eclipse on May 29, 1919 was the first verification of general relativity by an external team of scientists, brought Einstein and his theory to the attention of the general public, and ...
Will, Clifford M.
core   +2 more sources

Te Vacancy‐Driven Anomalous Transport in ZrTe5 and HfTe5

Advanced Physics Research, EarlyView.
Less is more! Recent discoveries in topological quantum materials have rekindled excitement for direct observation of quantum anomalies in a condensed matter physics laboratory, which is historically intractable in particle and cosmological physics. Using atomistic modeling this study sheds light on the source of the anomalous transport properties that
Elizabeth A. Peterson, Christopher Lane, Jian‐Xin Zhu   +2 more
wiley   +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

Bekenstein’s Entropy Bound-Particle Horizon Approach to Avoid the Cosmological Singularity

Entropy, 2020
The cosmological singularity of infinite density, temperature, and spacetime curvature is the classical limit of Friedmann’s general relativity solutions extrapolated to the origin of the standard model of cosmology.
James R. Powell, Rafael Lopez-Mobilia, Richard A. Matzner   +2 more
doaj   +1 more source

Probing time orientability of spacetime

European Physical Journal C: Particles and Fields, 2023
In general relativity, cosmology and quantum field theory, spacetime is assumed to be an orientable manifold endowed with a Lorentz metric that makes it spatially and temporally orientable.
N. A. Lemos, D. Müller, M. J. Rebouças
doaj   +1 more source

The Curious Concept That Almost Nobody Seemed to Care About at First: Virtual Particles in the Post‐War Period**

Berichte zur Wissenschaftsgeschichte, EarlyView.
Abstract Short‐lived, unobservable, and not subject to the usual rules of conservation of energy and momentum, virtual particles—an integral part of the conceptual framework of quantum field theory (QFT)—exhibit a number of curious characteristics which, in recent decades, have in part fueled important discussions about their ontological status ...
Jean‐Philippe Martinez
wiley   +1 more source