We review both the kinematics and dynamics of non-lorentzian theories their associated geometries. First, we introduce kinematical spacetimes symmetry algebras. Next, construct actions describing particle in some these spaces using method nonlinear realisations. explain relation with coadjoint orbit method. continue discussing three types gravity theories: Galilei gravity, Newton-Cartan Carroll...

It has been speculated that Lorentzian wormholes of the Morris-Thorne type might be allowed by the laws of physics at submicroscopic, e.g. Planck, scales and that a sufficiently advanced civilization might be able to enlarge them to classical size. The purpose of this paper is to explore the possibility that inflation might provide a natural mechanism for the enlargement of such wormholes to ma...

Just as for non-abelian gauge theories at strong coupling, discrete lattice methods are a natural tool in the study of non-perturbative quantum gravity. They have to reflect the fact that the geometric degrees of freedom are dynamical, and that therefore also the lattice theory must be formulated in a background-independent way. After summarizing the status quo of discrete covariant lattice mod...

v. dannon showed that spherical curves in e4 can be given by frenet-like equations, and he thengave an integral characterization for spherical curves in e4 . in this paper, lorentzian spherical timelike andspacelike curves in the space time 41 r are shown to be given by frenet-like equations of timelike andspacelike curves in the euclidean space e3 and the minkowski 3-space 31 r . thus, finding...

we study connected orientable spacelike hypersurfaces $x:m^{n}rightarrowm_q^{n+1}(c)$, isometrically immersed into the riemannian or lorentzian space form of curvature $c=-1,0,1$, and index $q=0,1$, satisfying the condition $~l_kx=ax+b$,~ where $l_k$ is the $textit{linearized operator}$ of the $(k+1)$-th mean curvature $h_{k+1}$ of the hypersurface for a fixed integer $0leq k

background: in general, measurements of solar ultraviolet (uv) radiation are related to horizontal surfaces. while the hu­mans walking and standing outdoors expose to the natural solar uv radiation, their eyes, cheeks, extremities, trunks, or many other anatomical sites are close to vertical plane and random orient to different directions. in this study, we character­ized the diurnal variations...

We summarize the main ideas of General Relativity and Lorentzian geometry, leading to a proof of the simplest of the celebrated Hawking-Penrose singularity theorems. The reader is assumed to be familiar with Riemannian geometry and point set topology. Introduction Historically, much of the development of Riemannian geometry has been driven by General Relativity. This theory models spacetime as ...

In this paper using the Clifford bundle formalism a Lagrangian theory of the Yang-Mills type (with a gauge fixing term and an auto interacting term) for the gravitational field in Minkowski spacetime is presented. It is shown how two simple hypothesis permits the interpretation of the formalism in terms of effective Lorentzian or teleparallel geometries. In the case of a Lorentzian geometry int...

The causal and metric structure of globally hyperbolic spacetimes is investigated from a C∗-algebra point of view related to part of Connes’ noncommutative geometry programme. No foliation of the spacetime by means of spacelike surfaces is employed, but the complete Lorentzian geometry is considered. Several results are produced. As a first result, Connes’ functional formula of the distance is ...

We theoretically model the near-field (NF) absorption for a multilayer micro-cavity (MMC) structure and investigate contribution of NF to dipole radiation power in top-emitting organic light-emitting diodes (OLEDs). The occurs due interaction between an evanescent wave with large in-plane vector planar metal layer vicinity radiation. analytical expressions MMC are derived from plane expansions ...