Sasaki manifolds admit a nowhere vanishing vector field and it is always possible to consider a Lorentz metric on them. Then we are able to obtain a classification result for compact Lorentz–Sasaki space forms.

A Lorentzian manifold is defined here as a smooth pseudoRiemannian manifold with a metric tensor of signature (2n + 1, 1). A Robinson manifold is a Lorentzian manifold M of dimension > 4 with a subbundle N of the complexification of TM such that the fibers of N → M are maximal totally null (isotropic) and [SecN,SecN ] ⊂ SecN . Robinson manifolds are close analogs of the proper Riemannian, Hermi...

In this paper we consider the images taken from pairs of parabolic catadioptric cameras separated by discrete motions. Despite the nonlinearity of the projection model, the epipolar geometry arising from such a system, like the perspective case, can be encoded in a bilinear form, the catadioptric fundamental matrix. We show that all such matrices have equal Lorentzian singular values, and they ...

A bstract Feynman’s iϵ prescription for quantum field theoretic propagators has a quite natural reinterpretation in terms of slight complex deformation the Minkowski space-time metric. Though originally strictly flat-space result, once reinterpreted this way, these ideas can be naturally extended first to semi-classical curved-spacetime QFT on fixed background geometry and then, (with more work...

The formalism of Greensite for treating the spacetime signature as a dynamical degree of freedom induced by quantum elds is considered, for spacetimes with nontrivial topology of the kind R 1 T, for varying D. It is shown that a dynamical origin for the Lorentzian signature is possible in the ve-dimensional space R T with small torus radius (periodic boundary conditions), as well as in four-dim...

If Einstein’s equations are to describe a field theory of gravity in Minkowski spacetime, then causality requires that the effective curved metric must respect the flat background metric’s null cone. The kinematical problem is solved using a generalized eigenvector formalism based on the Segré classification of symmetric rank 2 tensors with respect to a Lorentzian metric. Securing the correct r...

A non-relativistic Fokker-Planck equation for the electron distribution function is formulated incorporating the effects of stochastic acceleration by whistlermode waves and Coulomb collisions. The stationary solution f to the equation, subject to a zero-flux boundary condition, is found to be a generalized Lorentzian (or kappa) distribution, which satisfies f ∝ v for large velocity v, where κ ...

In this work we provide a recursive method of calculating the wavefunction XX spin chain coupled at both ends to non-Markovian reservoirs with arbitrary spectral density. The is based on appropriate handling time-dependent Schrodinger's equations motion in Laplace space and leads closed form solutions transformed amplitudes, for lengths as well initial conditions, within single-excitation subsp...