搜索结果: 1-15 共查到“理论天体物理学 gravity”相关记录15条 . 查询时间(0.109 秒)
We examine the existence of relativistic stars in f(T) modified gravity and explicitly construct several classes of static perfect fluid solutions. We derive the conservation equation from the complet...
Model-Independent Comparisons of Pulsar Timings to Scalar-Tensor Gravity
General Relativity Gravity Gravitation Scalar-Tensor Tensor-Scalar Neutron Stars Pulsars Binary Pulsars Double Pulsar
2011/10/14
Observations of pulsar timing provide strong constraints on scalar-tensor theories of gravity, but these constraints are traditionally quoted as limits on the microscopic parameters (like the Brans-Di...
Homogeneous Solutions of Quadratic Gravity
Quadratic gravity eff ective gravity homogenous geometries
2011/10/17
It is believed that soon after the Planck time, Einstein's general relativity theory should be corrected to an effective quadratic theory. In this work we present the 3+1 decomposition for the zero vo...
We show that in theories of generalised teleparallel gravity, whose Lagrangians are algebraic functions of the usual teleparallel Lagrangian, the action and the field equations are not invariant unde...
Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
Unified cosmic history theory Lorentz non-invariant models
2010/11/16
Classical generalization of general relativity is considered as gravitational alternative for unified description of the early-time inflation with late-time cosmic acceleration. The structure and cosm...
Topology of large scale structure as test of modified gravity
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2011/1/5
The genus of the iso-density contours is a robust measure of the topology of large-scale structure, and relatively insensitive to galaxies biasing and redshift-space distortions. We show that the grow...
The matter Lagrangian and the energy-momentum tensor in modified gravity with non-minimal coupling between matter and geometry
energy-momentum tensor modified gravity non-minimal coupling
2010/3/18
We show that in modified $f(R)$ type gravity models with non-minimal coupling between matter and geometry, both the matter Lagrangian, and the energy-momentum tensor, are completely and uniquely deter...
Geometry and observables in (2+1)-gravity
vacuum spacetimes (2+1)-gravity geometrical properties
2010/3/18
We review the geometrical properties of vacuum spacetimes in (2+1)-gravity with vanishing cosmological constant. We explain how these spacetimes are characterised as quotients of their universal cover...
Observational Constraints on Transverse Gravity: a Generalization of Unimodular Gravity
Transverse Gravity Unimodular Gravity
2010/3/19
We explore the hypothesis that the set of symmetries enjoyed by the theory that describes gravity is not the full group of diffeomorphisms Diff(M), as in General Relativity, but a maximal subgroup of ...
Quantum theory, gravity, and the standard model of particle physics : using the hints of today to build the final theory of tomorrow
Quantum theory gravity particle physics
2010/3/19
When a mountaineer is ascending one of the great peaks of the Himalayas she knows that an entirely new vista awaits her at the top, whose ramifications will be known only after she gets there. Her imm...
Why gravity is fundamental
gravity fundamental
2010/3/19
It is argued that the existence of a minimum size of spacetime may imply the fundamental existence of gravity as a geometric property of spacetime described by general relativity.
The Generalized Uncertainty Principle and Quantum Gravity Phenomenology
Quantum Gravity Phenomenology
2010/3/19
In this article we examine a Generalized Uncertainty Principle which differs from the Heisenberg Uncertainty Principle by terms linear and quadratic in particle momenta, as proposed by the authors in ...
Global Lorentzian geometry from lightlike geodesics: What does an observer in (2+1)-gravity see?
lightlike geodesics (2+1)-gravity
2010/3/19
We show how an observer could measure the non-local holonomy variables that parametrise the flat Lorentzian 3d manifolds arising as spacetimes in (2+1)-gravity. We consider an observer who emits light...
Holographic Superconductors in Hořava-Lifshitz Gravity
holographic superconductors Hoˇrava-Lifshitz gravity parameter of the detailed balance
2010/3/18
We study $(2+1)$-dimensional holographic superconductors in the Ho\v{r}ava-Lifshitz black hole without the condition of the detailed balance which has rich physics, i.e., changing the parameter of the...
Gravity duals for logarithmic conformal field theories
Gravity duals Logarithmic conformal field
2010/3/18
Logarithmic conformal field theories with vanishing central charge describe systems with quenched disorder, percolation or dilute self-avoiding polymers. In these theories the energy momentum tensor a...