Results 91 to 100 of about 42,432 (292)

Horizon thermodynamics and cosmological equations: a holographic-like connection between thermostatistical quantities on a cosmological horizon and in the bulk

European Physical Journal C: Particles and Fields, 2023
Horizon thermodynamics is expected to be related to the effective energy based on the energy density calculated from the Friedmann equation for a Friedmann–Robertson–Walker (FRW) universe.
Nobuyoshi Komatsu
doaj   +1 more source

Auxiliary “Massless” Spin-2 Field in De Sitter Universe [PDF]

International Journal of Theoretical Physics, 2010
For the tensor field of rank-2 there are two unitary irreducible representation (UIR) in de Sitter (dS) space denoted by $ ^{\pm}_{2,2}$ and $ ^{\pm}_{2,1}$ [1]. In the flat limit only the $ ^{\pm}_{2,2}$ coincides to the UIR of Poincar group, the second one becomes important in the study of conformal gravity.
Pejhan, H., Tanhayi, M. R., Takook, M. V.   +2 more
openaire   +2 more sources

Upacicalcet: A Novel Intravenous Calcimimetic Agent for Patients Undergoing Hemodialysis With Secondary Hyperparathyroidism

Therapeutic Apheresis and Dialysis, EarlyView.
ABSTRACT Secondary hyperparathyroidism (SHPT) is a common complication in patients receiving maintenance dialysis, driven by calcium and phosphate metabolism disturbances. Calcimimetics are central to the management of SHPT by enhancing calcium‐sensing receptor sensitivity and reducing parathyroid hormone secretion.
Fumihiko Koiwa, Daisuke Honda, Seigo Akari, Tadao Akizawa   +3 more
wiley   +1 more source

De Sitter space is sometimes not empty

Journal of High Energy Physics
Multiple lines of evidence suggest that the Hilbert space of an isolated de Sitter universe is one dimensional but can appear larger when probed by a gravitating observer.
Vijay Balasubramanian, Yasunori Nomura, Tomonori Ugajin   +2 more
doaj   +1 more source

The first heat: production of entanglement entropy in the early universe

Journal of High Energy Physics, 2019
Entanglement entropy (EE) of a spatial region quantifies correlations between the region and its surroundings. For a free scalar in the adiabatic vacuum in de Sitter space the EE is known to remain low, scaling as the surface area of the region. Here, we
Sergei Khlebnikov, Akhil Sheoran
doaj   +1 more source

Rest frame vacuum of the Proca field in the de Sitter expanding universe

European Physical Journal C: Particles and Fields, 2020
The general plane wave solutions of the Proca field in conformal charts of the de Sitter expanding universe are derived for arbitrary polarizations showing how the frequencies can be separated in rest frames, defining thus the rest frame vacuum of this ...
Ion I. Cotăescu
doaj   +1 more source

ANTI-DE SITTER ISLAND-UNIVERSES FROM 5D STANDING WAVES [PDF]

Modern Physics Letters A, 2010
We construct simple standing wave solutions in a 5D spacetime with a ghost-like scalar field. The nodes of these standing waves are "islands" of 4D anti-de Sitter spacetime. In the case of increasing (decreasing) warp factor, there are a finite (infinite) number of nodes and thus a finite (infinite) number of anti-de Sitter island-universes having ...
Gogberashvili M., Singleton D.
openaire   +4 more sources

Revealing the structure of land plant photosystem II: the journey from negative‐stain EM to cryo‐EM

FEBS Letters, EarlyView.
Advances in cryo‐EM have revealed the detailed structure of Photosystem II, a key protein complex driving photosynthesis. This review traces the journey from early low‐resolution images to high‐resolution models, highlighting how these discoveries deepen our understanding of light harvesting and energy conversion in plants.
Roman Kouřil
wiley   +1 more source

Mapping the evolution of mitochondrial complex I through structural variation

FEBS Letters, EarlyView.
Respiratory complex I (CI) is crucial for bioenergetic metabolism in many prokaryotes and eukaryotes. It is composed of a conserved set of core subunits and additional accessory subunits that vary depending on the organism. Here, we categorize CI subunits from available structures to map the evolution of CI across eukaryotes. Respiratory complex I (CI)
Dong‐Woo Shin, Tingting Chen, James A. Letts   +2 more
wiley   +1 more source

Reciprocal control of viral infection and phosphoinositide dynamics

FEBS Letters, EarlyView.
Phosphoinositides, although scarce, regulate key cellular processes, including membrane dynamics and signaling. Viruses exploit these lipids to support their entry, replication, assembly, and egress. The central role of phosphoinositides in infection highlights phosphoinositide metabolism as a promising antiviral target.
Marie Déborah Bancilhon, Bruno Mesmin
wiley   +1 more source