Results 1 to 10 of about 27,330 (221)
A tensor theory of space-time as a strained material continuum [PDF]
Class.Quant.Grav.27:035001,2010, 2009 The classical theory of strain in material continua is reviewed and generalized to space-time. Strain is attributed to "external" (matter/energy fields) and intrinsic sources fixing the global symmetry of the universe (defects in the continuum). A Lagrangian for space-time is worked out, adding to the usual Hilbert term an "elastic" contribution from ...
Radicella, Ninfa, Tartaglia, Angelo
arxiv +3 more sources
Thermodynamical analysis on a braneworld scenario with curvature corrections [PDF]
, 2011 We study the thermodynamics of some cosmological models based on modified gravity, a braneworld with induced gravity and curvature effect. Dark energy component seems necessary if the models are to approach thermal equilibrium in the long run.
Pavón, Diego, Radicella, Ninfa
arxiv +3 more sources
Massive gravitational waves from the Cosmic Defect theory [PDF]
AIP Conf.Proc.1241:1128-1133,2010, 2009 The Cosmic Defect theory (CD), which is presented elsewhere in this conference, introduces in the standard Einstein-Hilbert Lagrangian an elastic term accounting for the strain of space-time viewed as a four-dimensional physical continuum. In this framework the Ricci scalar acts as the kinetical term of the strain field whose potential is represented ...
Radicella, Ninfa, Tartaglia, Angelo
arxiv +5 more sources
Weak-Field Spherically Symmetric Solutions in $f(T)$ gravity [PDF]
Phys. Rev. D 91, 104014 (2015), 2015 We study weak-field solutions having spherical symmetry in $f(T)$ gravity; to this end, we solve the field equations for a non diagonal tetrad, starting from Lagrangian in the form $f(T)=T+\alpha T^{n}$, where $\alpha$ is a small constant, parameterizing the departure of the theory from GR.
Radicella, Ninfa, Ruggiero, Matteo Luca
arxiv +3 more sources
Kantowski-Sachs Universes sourced by a Skyrme fluid [PDF]
Phys.Rev. D91 (2015) 6, 063533, 2014 The Kantowski-Sachs cosmological model sourced by a Skyrme field and a cosmological constant is considered in the framework of General Relativity. Assuming a constant radial profile function for the hedgehog ansatz, the Skyrme contribution to Einstein equations is shown to be equivalent to an anisotropic fluid.
Parisi, Luca +2 more
arxiv +3 more sources
Constraining f(T) gravity in the Solar System [PDF]
JCAP08(2015)021, 2015 In the framework of $f(T)$ theories of gravity, we solve the field equations for $f(T)=T+\alpha T^{n}$, in the weak-field approximation and for spherical symmetry spacetime. Since $f(T)=T$ corresponds to Teleparallel Gravity, which is equivalent to General Relativity, the non linearity of the Lagrangian are expected to produce perturbations of the ...
Iorio, Lorenzo +2 more
arxiv +3 more sources
Constraints on Covariant Horava-Lifshitz Gravity from frame-dragging experiment [PDF]
, 2014 The effects of Horava-Lifshitz corrections to the gravito-magnetic field are analyzed. Solutions in the weak field, slow motion limit, referring to the motion of a satellite around the Earth are considered. The post-newtonian paradigm is used to evaluate constraints on the Horava-Lifshitz parameter space from current satellite and terrestrial ...
Lambiase, Gaetano +3 more
arxiv +3 more sources
Executive summary of the 2020 clinical practice guidelines for the management of hypertension in the Philippines. [PDF]
J Clin Hypertens (Greenwich), 2021 Abstract Hypertension is the most common cause of death and disability worldwide with its prevalence rising in low to middle income countries. It remains to be an important cause of morbidity and mortality in the Philippines with poor BP control as one of the main causes.
Ona DID +23 more
europepmc +2 more sources
Constraining massive gravity with recent cosmological data [PDF]
, 2012 A covariant formulation of a theory with a massive graviton and no negative energy state has been recently proposed as an alternative to the usual General Relativity framework. For a spatially flat homogenous and isotropic universe, the theory introduces modified Friedmann equations where the standard matter term is supplemented by four effective ...
J. R. Bond +3 more
arxiv +3 more sources
O corpo feminino, o movimento e a fluidez: as ninfas em Victor Meirelles e Pedro Américo
Visualidades, 2017 A presente pesquisa aborda a construção corpórea feminina na pintura brasileira do século XIX. O estudo visa problematizar os corpos femininos formulados a partir dos parâmetros da recém instaurada Academia de Artes no Brasil em diálogo com as questões ...
Daniela Queiroz Campos
doaj +3 more sources