FINSLER AND LAGRANGE GEOMETRIES IN EINSTEIN AND STRING GRAVITY

We review the current status of Finsler–Lagrange geometry and generalizations. The goal is to aid non-experts on Finsler spaces, but physicists and geometers skilled in general relativity and particle theories, to understand the crucial importance of such geometric methods for applications in modern physics. We also would like to orient mathematicians working in generalized Finsler and Kähler geometry and geometric mechanics how they could perform their results in order to be accepted by the community of "orthodox" physicists. Although the bulk of former models of Finsler–Lagrange spaces where elaborated on tangent bundles, the surprising result advocated in our works is that such locally anisotropic structures can be modeled equivalently on Riemann–Cartan spaces, even as exact solutions in Einstein and/or string gravity, if nonholonomic distributions and moving frames of references are introduced into consideration. We also propose a canonical scheme when geometrical objects on a (pseudo) Riemannian space are nonholonomically deformed into generalized Lagrange, or Finsler, configurations on the same manifold. Such canonical transforms are defined by the coefficients of a prime metric and generate target spaces as Lagrange structures, their models of almost Hermitian/Kähler, or nonholonomic Riemann spaces. Finally, we consider some classes of exact solutions in string and Einstein gravity modeling Lagrange–Finsler structures with solitonic pp-waves and speculate on their physical meaning.

BRANE SOLUTIONS WITH A QUADRATIC POTENTIAL IN STRING FRAME

We have examined brane world solutions for the low energy effective string gravity action coupled with a quadratic dilaton potential in string frame. For a negative bulk cosmological constant, static 3-brane solutions exist. Their properties are analyzed depending on the quadratic potential parameters. It is found that a brane solution in a curved bulk space in Einstein frame corresponds to a dilaton solution in flat space in string frame.

RICCI FLOWS AND SOLITONIC pp-WAVES

We find exact solutions describing Ricci flows of four-dimensional pp-waves nonlinearly deformed by two-/three-dimensional solitons. Such solutions are parametrized by five-dimensional metrics with generic off-diagonal terms and connections with nontrivial torsion which can be related, for instance, to antisymmetric tensor sources in string gravity. There are defined nontrivial limits to four-dimensional configurations and the Einstein gravity.

GAUGE/STRING-GRAVITY DUALITY AND FROISSART BOUND

The gauge/string-gravity duality correspondence opened renewed hope and possibility to address some of the fundamental and non-perturbative QCD problems of in particle physics, such as hadron spectrum and Regge behavior of the scattering amplitude at high energies. One of the most fundamental and long-standing problems is the high energy behavior of the total cross-sections. According to a series of exhaustive tests by the COMPETE group, (1) total cross sections have a universal Heisenberg behavior in energy corresponding to the maximal energy behavior allowed by the Froissart bound, i.e., A+B ln 2(s/s0) with B~0.32 mb and s0~34.41 GeV2 for all reactions, and (2). The factorization relation among σpp,even, σγp and σγγ is well satisfied by experiments. I discuss the recent interesting application of the gauge/string-gravity duality of AdS/CFT correspondence with a deformed background metric so as to break the conformal symmetry that lead to the Heisenberg behavior of rising total cross sections, and present some preliminary results on the high energy QCD from Planckian scattering in AdS and black-hole production.