Results 71 to 80 of about 26,635,104 (298)
Emergence of running vacuum energy in f(R, T) gravity : Observational constraints
Physics Letters BIn this work, we present a new analysis for f(R, T) gravity by exploring the energy momentum tensor. We demonstrate that f(R, T) gravity with the form f(R,T)=R+2κ2λT−2Λ is equivalent to Running Vacuum Energy (RVE), which interacts with the components of ...
Ahmed Errahmani +4 more
doaj +1 more source
Compact relativistic geometries in $f(R,G)$ gravity [PDF]
, 2022 One of the possible potential candidates for describing the universe's rapid expansion is modified gravity. In the framework of the modified theory of gravity $f(R,G)$, the present work features the materialization of anisotropic matter, such as compact ...
Yousaf, Z. +5 more
core +1 more source
Cosmography of the f(R,T) gravity theory
, 2021 Currently, in order to explain the accelerated expansion phase of the universe, several alternative approaches have been proposed, among which the most common are dark energy models and alternative theories of gravity. Although these approaches rest on very different physical aspects, it has been shown that both are in agreement with the data in the ...
Farias, I. S., Moraes, P. H. R. S.
openaire +2 more sources
Embedded Direct Ink Writing of Thermoset and Elastomeric Polymers via Frontal Polymerization
Advanced Functional Materials, EarlyView.Embedded frontal polymerization direct ink writing (FP‐DIW) combines frontal ring‐opening metathesis polymerization with embedded 3D printing to decouple deposition from curing. A yield‐stress support bath stabilizes low‐viscosity inks, while on‐demand thermal initiation enables controlled front propagation. This approach expands the accessible feature
Mohammad Tanver Hossain +12 more
wiley +1 more source
Extended Theories of Electrodynamics in $f(R)$ Gravity
12 Pages; Accepted for publication in Annals of ...
Bajardi, Francesco +3 more
openaire +3 more sources
Some aspects of reconstruction using a scalar field in f(T) gravity
European Physical Journal C: Particles and Fields, 2017 General relativity characterizes gravity as a geometric property exhibited on spacetime by massive objects, while teleparallel gravity achieves the same results at the level of equations, by taking a torsional perspective of gravity.
Soumya Chakrabarti +2 more
doaj +1 more source
Genetically Programmed Shape‐Morphing of Engineered Living Materials
Advanced Functional Materials, EarlyView.Here, bacterial and mammalian engineered living materials (ELMs) are presented, in which living cells direct genetically programmed and enzymatically mediated shape‐morphing. The resulting deformation and shape‐recovery can be actuated in a genetically controlled manner by an ELM incorporating out‐of‐equilibrium counteracting biochemical reactions with
Jan Becker +7 more
wiley +1 more source
How a projectively flat geometry regulates F(R)-gravity theory?
, 2021 In the present paper we examine a projectively flat spacetime solution of F(R)-gravity theory. It is seen that once we deploy projective flatness in the geometry of the spacetime, the matter field has constant energy density and isotropic pressure.
De, Avik +3 more
core +1 more source
Time-Machines Construct in $f(\mathcal{R},\mathcal{A},A^{μν}\,A_{μν})$ and $f(\mathcal{R})$ Modified Gravity Theories [PDF]
In this paper, our objective is to explore a time-machine space-time formulated in general relativity, as introduced by Li (Phys. Rev. D {\bf 59}, 084016 (1999)), within the context of modified gravity theories.
Ahmed, F. +2 more
core +1 more source
f(R) theories of gravity in the Palatini approach matched with observations
General Relativity and Gravitation, 2006 We investigate the viability of f(R) theories in the framework of the Palatini approach as solutions to the problem of the observed accelerated expansion of the universe. Two physically motivated popular choices for f(R) are considered: power law, f(R) = βR^n, and logarithmic, f(R) = α\ln{R}.
CAPOZZIELLO, SALVATORE +2 more
openaire +6 more sources