arXiv subjects

Sergiu Vacaru

Publications and source records attributed to Sergiu Vacaru.

5 recordsLinked to original sources

arXiv2015

Modified Dynamical Supergravity Breaking and Off-Diagonal Super-Higgs Effects

We argue that generic off-diagonal vacuum and nonvacuum solutions for Einstein manifolds mimic physical effects in modified gravity theories (MGTs) and encode certain models of the $f(R,T,...)$, Hořava type with dynamical Lorentz symmetry breaking, induced effective mass for the graviton etc. Our main goal is to investigate the dynamical breaking of local supersymmetry determined by off-diagonal solutions in MGTs and encoded as effective Einstein spaces. This includes the Deser-Zumino super-Higgs effect, for instance, for a one-loop potential in a (simple but representative) model of $\mathcal{N}=1, D=4$ supergravity. We develop and apply new geometrical techniques which allows us to decouple the gravitational field equations and integrate them in a very general form with the metric and vielbein fields depending on all the spacetime coordinates via means of various generating and integration functions and parameters. We study how solutions in MGTs may be related to the dynamical generation of a gravitino mass and supersymmetry breaking.

hep-th↗

arXiv2003

Horizons and Geodesics of Black Ellipsoids with Anholonomic Conformal Symmetries

The horizon and geodesic structure of static configurations generated by anisotropic conformal transforms of the Schwarzschild metric is analyzed. We construct the maximal analytic extension of such off--diagonal vacuum metrics and conclude that for small deformations there are different classes of vacuum solutions of the Einstein equations describing "black ellipsoid" objects. This is possible because, in general, for off--diagonal metrics with deformed non--spherical symmetries and associated anholonomic frames the conditions of the uniqueness black hole theorems do not hold.

gr-qc↗

arXiv2003

Horizons and Geodesics of Black Ellipsoids

We analyze the horizon and geodesic structure of a class of 4D off--diagonal metrics with deformed spherical symmetries, which are exact solutions of the vacuum Einstein equations with anholonomic variables. The maximal analytic extension of the ellipsoid type metrics are constructed and the Penrose diagrams are analyzed with respect to adapted frames. We prove that for small deformations (small eccentricities) there are such metrics that the geodesic behaviour is similar to the Schwarzcshild one. We conclude that some vacuum static and stationary ellipsoid configurations may describe black ellipsoid objects.

gr-qc↗

arXiv2002

Noncommutative Finsler Geometry, Gauge Fields and Gravity

The work extends the A. Connes' noncommutative geometry to spaces with generic local anisotropy. We apply the E. Cartan's anholonomic frame approach to geometrical models and physical theories and develop the nonlinear connection formalism for projective module spaces. Examples of noncommutative generation of anholonomic Riemann, Finsler and Lagrange spaces are analyzed. We also present a research on noncommutative Finsler--gauge theories, generalized Finsler gravity and anholonomic (pseudo) Riemann geometry which appear naturally if anholonomic frames (vierbeins) are defined in the context of string/M--theory and extra dimension Riemann gravity.

math-ph↗

arXiv2002

Spinors and Space-Time Anisotropy

This is the first monograph on the geometry of anisotropic spinor spaces and its applications in modern physics. The main subjects are the theory of gravity and matter fields in spaces provided with off--diagonal metrics and associated anholonomic frames and nonlinear connection structures, the algebra and geometry of distinguished anisotropic Clifford and spinor spaces, their extension to spaces of higher order anisotropy and the geometry of gravity and gauge theories with anisotropic spinor variables. The book summarizes the authors' results and can be also considered as a pedagogical survey on the mentioned subjects.

gr-qc↗