Results 31 to 40 of about 292,024 (345)
European Physical Journal C: Particles and Fields, 2023 The observational data of primordial black holes and scalar-induced gravitational waves can constrain the primordial curvature perturbation at small scales. We parameterize the primordial curvature perturbation by a broken power law form and find that it
Zhu Yi, Qin Fei
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A rigidity theorem for nonvacuum initial data [PDF]
, 2001 In this note we prove a theorem on non-vacuum initial data for general relativity. The result presents a ``rigidity phenomenon'' for the extrinsic curvature, caused by the non-positive scalar curvature.
Choquet-Bruhat Y. +10 more
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Scalar Curvature of a Causal Set [PDF]
Physical Review Letters, 2010 A one parameter family of retarded linear operators on scalar fields on causal sets is introduced. When the causal set is well approximated by 4 dimensional Minkowski spacetime, the operators are Lorentz invariant but nonlocal, are parametrized by the scale of the nonlocality, and approximate the continuum scalar D'Alembertian square when acting on ...
Benincasa, Dionigi Maria Teofilo +1 more
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Heterotic reduction of Courant algebroid connections and Einstein–Hilbert actions
Nuclear Physics B, 2016 We discuss Levi-Civita connections on Courant algebroids. We define an appropriate generalization of the curvature tensor and compute the corresponding scalar curvatures in the exact and heterotic case, leading to generalized (bosonic) Einstein–Hilbert ...
Branislav Jurčo, Jan Vysoký
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Metric Inequalities with Scalar Curvature [PDF]
Geometric and Functional Analysis, 2018 We establish several inequalities for manifolds with positive scalar curvature and, more generally, for the scalar curvature bounded from below, in the spirit of the classical bound on the distances between conjugates points in surfaces with positive sectional curvature.
Misha Gromov, Misha Gromov
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Properties of Berwald scalar curvature [PDF]
Frontiers of Mathematics in China, 2020 published on Front.
Ming Li, Lihong Zhang
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On the transverse Scalar Curvature of a Compact Sasaki Manifold
Complex Manifolds, 2014 We show that the standard picture regarding the notion of stability of constant scalar curvature metrics in Kähler geometry described by S.K. Donaldson [10, 11], which involves the geometry of infinitedimensional groups and spaces, can be applied to the ...
He Weiyong
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Non-negative versus positive scalar curvature
, 2020 We show that results about spaces or moduli spaces of positive scalar curvature metrics proved using index theory can typically be extended to non-negative scalar curvature metrics.
Schick, Thomas, Wraith, David J.
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Two dimensional kinematic surfaces with constant scalar curvature in Lorentz-Minkowski 7-space
Nonlinear Engineering, 2017 In this paper we analyzed the problem of studying locally the scalar curvature S of the two dimensional kinematic surfaces obtained by the homothetic motion of a helix in Lorentz-Minkowski space E17 $\text{E}^7_1$ .
Solouma E. M., Wageeda M. M.
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Black Holes have Intrinsic Scalar Curvature
Reports in Advances of Physical Sciences, 2023 The scalar curvature R is invariant under isometric symmetries (distance invariance) associated with metric spaces. Gravitational Riemannian manifolds are metric spaces.
P. D. Morley
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