Results 161 to 170 of about 60,199 (278)

The entropy of dynamical de Sitter horizons

European Physical Journal C: Particles and Fields
We propose a new formula for the entropy of a dynamical cosmological event horizon, which is valid to leading order for perturbations of a stationary asymptotically de Sitter spacetime.
Jinan Zhao
doaj   +1 more source

Zero average values of cosmological perturbations as an indispensable condition for the theory and simulations. [PDF]

Eur Phys J C Part Fields, 2015
Eingorn M, Brilenkov M, Vlahovic B.
europepmc   +1 more source

Cosmological Perturbations [PDF]

Searching for New Physics at Small and Large Scales, 2013
openaire   +1 more source

Different Transient Phenomena at the Edges of Traveling Foreshocks

Journal of Geophysical Research: Space Physics, Volume 131, Issue 1, January 2026.
Abstract Past kinetic simulations and spacecraft observations have shown that traveling foreshocks (TFs) are bounded by either foreshock compressional boundaries (FCBs) or foreshock bubbles (FBs). Here we present four TFs with a different kind of structure appearing at one of their edges.
Primož Kajdič, Xochitl Blanco‐Cano, Diana Rojas‐Castillo, Nojan Omidi   +3 more
wiley   +1 more source

Primordial gravitational waves assisted by cosmological scalar perturbations

European Physical Journal C: Particles and Fields
Primordial gravitational waves are a crucial prediction of inflation theory, and their detection through their imprints on the cosmic microwave background is actively being pursued. However, these attempts have not yet been successful.
Yan-Heng Yu, Sai Wang
doaj   +1 more source

Perturbations in loop quantum cosmology [PDF]

, 2014
William Nelson, Iván Agulló, Abhay Ashtekar   +2 more
openalex   +1 more source

Kinetic Modeling of Inertial Alfvén Waves in the Solar Corona: Implications for Heating and Particle Acceleration

Journal of Geophysical Research: Space Physics, Volume 131, Issue 1, January 2026.
Abstract Recent observations from Parker Solar Probe and Solar Orbiter highlight the importance of Alfvén waves in solar coronal heating and particle acceleration. In this study, we investigate inertial Alfvén waves (IAWs), which operate at electron inertial scales, as a potential mechanism for plasma heating and charged particle acceleration in the ...
S. Ayaz, Gary P. Zank, Imran A. Khan, Andreas Shalchi, L.‐L. Zhao, Yeimy J. Rivera   +5 more
wiley   +1 more source

Evolution of perturbations in the model of Tsallis holographic dark energy

Physics Letters B
We investigated evolution of metric and density perturbations for Tsallis model of holographic dark energy with energy density ∼L2γ−4, where L is length of event horizon or inverse Hubble parameter and γ is parameter of non-additivity close to 1. Because
Artyom V. Astashenok, Alexander S. Tepliakov   +1 more
doaj   +1 more source

Inflation and the Theory of Cosmological Perturbations [PDF]

, 2002
Antonio Riotto
openalex   +1 more source

Stratigraphy of Carbonate‐Bearing Rocks at the Margin of Jezero Crater, Mars: Evidence for Shoreline Processes?

Journal of Geophysical Research: Planets, Volume 131, Issue 1, January 2026.
Abstract Martian carbonate‐bearing rocks are compelling targets for exploration because they preserve detailed records of past aqueous processes, climate, and habitability. The Margin unit in Jezero crater is a distinct olivine‐ and carbonate‐bearing unit stratigraphically underlying the western fan, lining the inner margin of the western crater rim ...
Alexander J. Jones, Sanjeev Gupta, Robert Barnes, Briony H. N. Horgan, Kenneth H. Williford, Gerhard Paar, Kathryn. M. Stack, Bradley J. Garzcynski, Eleni Ravanis, Candice C. Bedford, Justin I. Simon, Athanasios Klidaras, Linda C. Kah, James F. Bell, Justin Maki, Stephen W. Lokier, Adrian Brown, Nathan R. Williams, Sanna Alwmark, Jorge I. Núñez, Fred Calef, Larry Crumpler, Alicia Vaughan, Libby R. W. Ives, Sam Gwizd, Ken Farley, Christian Tate, Nicolas Randazzo, Olivier Beyssac, Gwénaël Caravaca   +29 more
wiley   +1 more source