搜索结果: 1-10 共查到“天文学 Scalar-Tensor”相关记录10条 . 查询时间(0.298 秒)
Inflationary non-Gaussianities in the most general second-order scalar-tensor theories
Inflationary non-Gaussianities in the most general second-order scalar-tensor theories
2011/10/14
For very general scalar-field theories in which the equations of motion are at second-order, we evaluate the three-point correlation function of primordial scalar perturbations generated during inflat...
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...
Asymptotically safe gravity as a scalar-tensor theory and its cosmological implications
Asymptotically gravity scalar-tensor theory cosmological implications
2011/10/14
We study asymptotically safe gravity with Einstein-Hilbert truncation taking into account the renormalization group running of both gravitational and cosmological constants. We show the classical beha...
On the redundancy of operators and the bispectrum in the most general second-order scalar-tensor theory
redundancy operators bispectrum general second-order scalar-tensor theory
2011/10/19
In this short note we explain how to use the linear equation of motions to simplify the third-order action for the cosmological fluctuations. No field redefinition is needed in this exact procedure wh...
Time-varying G in shift-symmetric scalar-tensor theories with a Vainshtein mechanism
shift-symmetric scalar-tensor theories Vainshtein mechanism
2011/10/18
We show that the current bounds on the time variation of the Newton constant G can put severe constraints on many interesting scalar-tensor theories which possess a shift symmetry and a nonminimal mat...
An exact cosmological solution of a Scalar-Tensor Gravity theory compatible with the $\Lambda$CDM model
exact cosmological solution Scalar-Tensor Gravity theory compatible $\Lambda$CDM model
2010/11/15
consider the massive Scalar-Tensor theory in the Jordan frame F() = K22,Z() = 1, and U() = (1/2)m22, F() corresponds to a constant Brans-Dicke parameter !BD = 1/4K2. The constaint of the solar s...
Scalar-Scalar, Scalar-Tensor, and Tensor-Tensor Correlators from Anisotropic Inflation
Scalar-Tensor Scalar-Scalar Tensor-Tensor Anisotropic Inflation
2010/3/22
We compute the phenomenological signatures of a model (Watanabe et al' 09) of anisotropic inflation driven by a scalar and a vector field. The action for the vector is U(1) invariant, and the model is...
On Current-Carrying Cosmic Strings and the Generalized Rainich Algebra in Scalar-Tensor Gravities
Current-Carrying Cosmic Strings the Generalized Rainich Algebra Scalar-Tensor Gravities
2010/10/15
We obtain exact solutions for a static and charged cosmic string in a Einstein-Maxwell-Dilaton theory of a scalar-tensor type in (3+1)-Dimensions. This theory is specified by the dilaton field f, the ...
Phase Space Solutions in Scalar-Tensor Cosmological Models
Phase Space Solutions Scalar-Tensor Cosmological Models
2010/10/15
An analysis of the solutions for the field equations of generalized scalar-tensor theories of gravitation is performed through the study of the geometry of the phase space and the stability of the sol...
Remarks on Some Vacuum Solutions of Scalar-Tensor Cosmological Models
Vacuum Solutions Scalar-Tensor Cosmological Models
2010/10/21
We present a class of exact vacuum solutions corresponding to de Sitter and warm inflation models in the framework of scalar-tensor cosmologies. We show that in both cases the field equations reduce t...