in this paper, we study spacelike dual biharmonic curves. we characterize spacelike dual biharmonic curves in terms of their curvature and torsion in the lorentzian dual heisenberg group . we give necessary and sufficient conditions for spacelike dual biharmonic curves in the lorentzian dual heisenberg group . therefore, we prove that all spacelike dual biharmonic curves are spacelike dual heli...

The implementation of the Debye, narrowband Lorentzian, and wideband Lorentzian dielectric and magnetic media in the numerical tool EZ-FDTD developed at the University of Missouri-Rolla (UMR is described. This tool allows efficient and robust full-wave finite-difference time-domain modeling of different complex electromagnetic structures. Algorithms for dispersive media use the linear recursive...

By referring to theorems of Donaldson and Hitchin, we exhibit a rigorous AdS/CFTtype correspondence between classical 2 + 1 dimensional vacuum general relativity theory on Σ× R and SO(3) Hitchin theory (regarded as a classical conformal field theory) on the spacelike past boundary Σ, a compact, oriented Riemann surface of genus greater than one. More precisely, we prove that if over Σ with a fi...

In this work it is shown that a necessary condition for the completeness of the geodesics of left invariant pseudo-Riemannian metrics on Lie groups is also sufficient in the case of 3-dimensional unimodular Lie groups, and not sufficient for 3-dimensional non unimodular Lie groups. As a consequence it is possible to identify, amongst the compact locally homogeneous Lorentzian 3-manifolds with n...

The boundary states for AdS 2 D-branes in Lorentzian AdS 3 space-time are presented. AdS 2 D-branes are algebraically defined by twisted Dirichlet boundary conditions and are located on twisted conjugacy classes of SL(2,R). Using free field representation of symmetry currents in the SL(2,R) WZNW model, the twisted Dirichlet gluing conditions among currents are translated to matching conditions ...

By using variational methods, we study the existence and multiplicity of trajec-tories under a vectorial potential on (standard) stationary Lorentzian manifolds possibly with boundary. 1. Introduction and statement of the results. The pair (ᏸ,g) is called Lorentzian manifold if ᏸ is a connected finite-dimensional smooth manifold with dim ᏸ ≥ 2 and g is a Lorentzian metric on ᏸ, that is, g is a ...

We consider a simplicial minisuperspace model based on a cone over the α4 triangulation of the 3−sphere, in the presence of a massive scalar field, φ, with arbitrary scalar coupling term ηRφ. By restricting all the interior edge lengths and all the boundary edge lengths to be equivalent and the scalar field to be homogenous on the 3−space, we obtain a two dimensional minisuperspace model {si, φ...

We implement Wilson fermions on 2D Lorentzian triangulation and determine the spectrum of the Dirac-Wilson operator. We compare it to the spectrum of the corresponding operator in the Euclidean background. We use fermionic particle to probe the fractal properties of Lorentzian gravity coupled to c = 1/2 and c = 4 matter. We numerically determine the scaling exponent of the mass gap M ∼ N −1/dH ...

A classical result in Lorentzian geometry states that a strongly causal spacetime is globally hyperbolic if and only if the Lorentzian distance is finite valued for every metric choice in the conformal class. It is proven here that a non-total imprisoning spacetime is globally hyperbolic if and only if for every metric choice in the conformal class the Lorentzian distance is continuous. Moreove...