Results 71 to 80 of about 68,577 (262)

Dark energy and modified gravity [PDF]

, 2010
Explanations of the late-time cosmic acceleration within the framework of general relativity are plagued by difficulties. General relativistic models are mostly based on a dark energy field with fine-tuned, unnatural properties. There is a great variety of models, but all share one feature in common -- an inability to account for the gravitational ...
Durrer, Ruth, Maartens, Roy
openaire   +4 more sources

New modified mimetic gravity [PDF]

International Journal of Geometric Methods in Modern Physics, 2014
A modified Mimetic gravity (MMG) is proposed as a generalization of general relativity. The model contains a physical metric which is the function of an auxiliary (unphysical) metric and a Lyra's metric. We construct different kinds of conformally invariant models in different levels of the expansion parameter λ. This model phenomenologically has been
Momeni, Davood, Altaibayeva, Aziza, Myrzakulov, Ratbay   +2 more
openaire   +2 more sources

Toward the Alleviation of the H₀ Tension in Myrzakulov f(R,T) Gravity

Universe
In this work, we provide a promising way to alleviate the Hubble tension within the framework of Myrzakulov f(R,T) gravity. The latter incorporates both curvature and torsion under a non-special connection. We consider the f(R,T)=R+αR2 class, which leads
Mashael A. Aljohani, Emad E. Mahmoud, Koblandy Yerzhanov, Almira Sergazina   +3 more
doaj   +1 more source

Rainbow Gravity Corrections to the Entropic Force

Advances in High Energy Physics, 2018
The entropic force attracts a lot of interest for its multifunctional properties. For instance, Einstein’s field equation, Newton’s law of gravitation, and the Friedmann equation can be derived from the entropic force. In this paper, utilizing a new kind
Zhong-Wen Feng, Shu-Zheng Yang
doaj   +1 more source

On Extensions of the Starobinsky Model of Inflation

Physical Sciences Forum, 2023
We propose inflationary models that are one-parametric generalizations of the Starobinsky R+R2 model. Using the conformal transformation, we obtain scalar field potentials in the Einstein frame that are one-parametric generalizations of the potential for
Vsevolod Ivanov, Sergei Ketov, Ekaterina Pozdeeva, Sergey Vernov   +3 more
doaj   +1 more source

Stretching the Printability Metric in Direct‐Ink Writing with Highly Extensible Yield‐Stress Fluids

Advanced Functional Materials, EarlyView.
This study introduces “drawability” as a new metric for assessing printability in direct‐ink writing, focusing on gap‐spanning performance and speed robustness. By designing yield‐stress fluids with high extensibility, we demonstrate that extensional strain‐to‐break significantly enhances printability.
Chaimongkol Saengow, Samya Sen, Joaquin Yus, Eliza E. Lovrich, Amanda G. Hoika, Kelly M. Chang, Arielle A. Pfeil, Nellie Haug, Amy J. Wagoner Johnson, Randy H. Ewoldt   +9 more
wiley   +1 more source

Schwarzschild-type black holes in Starobinsky-Bel-Robinson gravity

Physics Letters B, 2023
We study physical properties of a Schwarzschild-type black hole in the framework of the recently proposed Starobinsky-Bel-Robinson (SBR) modified theory of gravity, working perturbatively in the coupling constant.
Ruben Campos Delgado, Sergei V. Ketov
doaj   +1 more source

Electrocapillary Modulated Interfacial Tension Amplifies Liquid Metal Transduction

Advanced Functional Materials, EarlyView.
This study presented an electrocapillary‐enhanced magnetohydrodynamic pumping strategy that harnesses the Lorentz force and interfacial tension modulation of liquid metal droplets to achieve amplified fluidic power. The system enabled low‐voltage, self‐oscillating fluidic transduction with enhanced pressure and flow generation, supporting compact ...
Saba Firouznia, Ciqun Xu, Michael D. Dickey, Jonathan Rossiter   +3 more
wiley   +1 more source

Earthquakes as Probing Tools for Gravity Theories

Universe
We propose a novel method for testing gravity models using seismic waves’ velocities. By imposing observational constraints on Earth’s moment of inertia and mass, we rigorously limit the gravitational models’ parameters within a 2σ accuracy.
Aleksander Kozak, Aneta Wojnar
doaj   +1 more source

Off-diagonal cosmological solutions in emergent gravity theories and Grigory Perelman entropy for geometric flows

European Physical Journal C: Particles and Fields, 2021
We develop an approach to the theory of relativistic geometric flows and emergent gravity defined by entropy functionals and related statistical thermodynamics models. Nonholonomic deformations of G.
Sergiu I. Vacaru, Elşen Veli Veliev, Laurenţiu Bubuianu   +2 more
doaj   +1 more source