Results 61 to 70 of about 51,813 (205)

Anselm's Temporal‐Ontological Proof

Noûs, EarlyView.
ABSTRACT In his Reply to Gaunilo, Anselm presented two additional arguments for the existence of God beyond those that appear in the Proslogion. In “The Logical Structure of Anselm's Argument,” Robert M. Adams isolates each. One, he develops into a modal ontological argument along the lines of other 20th century ontological arguments (e.g., those of ...
Daniel Rubio
wiley   +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

Quantum Cosmology: Cosmology directly linked to the Planck Scale in General Relativity Theory and Newton Gravity

, 2023
We will in this paper demonstrate that there is a link between cosmology and the Planck scale. It has in recent years been shown that the Planck length can be found totally independent on \(G\), \(\hbar\) and \(c\) and that a series of cosmological predictions can be predicted only from two constants, namely the Planck length and the speed of gravity ...
openaire   +1 more source

The Concept of Revolution in the Sciences: Michael Polanyi's Differences With Thomas Kuhn on Scientific Revolutions

Natural Sciences, Volume 6, Issue 3, July 2026.
ABSTRACT Thomas Kuhn's The Structure of Scientific Revolutions (1962) was a blockbuster publication that problematized notions about the origins and nature of scientific revolutions. What became Kuhn's famous rubrics of “normal science” and “paradigms” were similar to concepts of “tacit knowledge” and scientific “frameworks” or “dogmas” in Michael ...
Mary Jo Nye
wiley   +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

Photon‐Sphere Modes in Curved Optical Microcavities: A Black‐Hole Analogue Laser

Advanced Science, Volume 13, Issue 28, 18 May 2026.
An optical analogue of a Schwarzschild black hole is realized using curved microcavities that preserve light‐like geodesics. A new family of laser modes confined around the photon sphere is identified alongside conventional whispering‐gallery modes. Analytical theory, numerical simulations, and experiments reveal curvature‐induced confinement, enabling
Chenni Xu, Aswathy Sundaresan, Nazire‐Begüm Kazkal, Clement Lafargue, Lior Zarfaty, Li‐Gang Wang, Ofek Birnholtz, Dominique Decanini, Melanie Lebental, Patrick Sebbah   +9 more
wiley   +1 more source

Signature change events: A challenge for quantum gravity?

, 2010
Within the framework of either Euclidian (functional-integral) quantum gravity or canonical general relativity the signature of the manifold is a priori unconstrained.
Alty L, Ambjorn J Loll R Watabiki Y Westra W Zohren S, Angela White, Barceló C, Basu S, Calzetta E A Hu B L, Calzetta E A Hu B L, Dowker F, Dray T, Dray T Hellaby C, Elizalde E, Ellis G, Gibbons G W, Greensite J, Hawking S W, Hawking S W, Hawking S W, Hawking S W, Hayward S A, Hayward S A, Hayward S A, Hayward S A, Hayward S A, Hayward S A, Horowitz G T, Landau L D, Liberati S, Liberati S Jacobson T A Mattingly D, Manogue T Dray C A, Matt Visser, Mattingly D, Mattingly D, Merzbacher E, Odintsov S D, Schutzhold R Unruh W G, Silke Weinfurtner, Sylvester J J, Teitelboim C, Visser M, Visser M, Visser M, Visser M, Visser M, Visser M Barceló C Liberati S, Weinfurtner S, Weinfurtner S, Weinfurtner S, Weinfurtner S Jain P Visser M Gardiner C W   +47 more
core   +2 more sources

Exactly solvable quantum cosmologies from two killing field reductions of general relativity

Nuclear Physics B, 1989
Abstract An exact and, possibly, general solution to the quantum constraints is given for the sector of general relativity containing cosmological solutions with two space-like, commuting, Killing fields. The dynamics of these model space-times, which are known as Gowdy space-times, is formulated in terms of Ashtekar's new variables. The quantization
Viqar Husain, Lee Smolin
openaire   +1 more source

Deforming the Double‐Scaled SYK and Reaching the Stretched Horizon From Finite Cutoff Holography

Fortschritte der Physik, Volume 74, Issue 5, May 2026.
ABSTRACT We study the properties of the double‐scaled SYK (DSSYK) model under chord Hamiltonian deformations based on finite cutoff holography for general dilaton gravity theories with Dirichlet boundaries. The formalism immediately incorporates a lower‐dimensional analog of TT¯(+Λ2)$\text{T}\overline{\text{T}}(+\Lambda _2)$ deformations, denoted T2 ...
Sergio E. Aguilar‐Gutierrez
wiley   +1 more source

Quantum suppression of the generic chaotic behavior close to cosmological singularities

, 2004
In classical general relativity, the generic approach to the initial singularity is very complicated as exemplified by the chaos of the Bianchi IX model which displays the generic local evolution close to a singularity.
C. Rovelli, Ghanashyam Date, M. Bojowald, Martin Bojowald, V. A. Belinskii   +4 more
core   +1 more source