Replica treatment of non-Hermitian disordered Hamiltonians

We employ the fermionic and bosonic replicated nonlinear sigma models to treat Ginibre unitary, symplectic, and orthogonal ensembles of non-Hermitian random matrix Hamiltonians. Using saddle point approach combined with Borel resummation procedure we derive the exact large-N results for microscopic density of states in all three ensembles. We also obtain tails of the density of states as well the two-point function for the unitary ensemble.Comment: REVTeX 3.1, 13 pages, 1 figure; typos fixed (v2

A quantum-mechanical perspective on linear response theory within polarizable embedding

The derivation of linear response theory within polarizable embedding is carried out from a rigorous quantum-mechanical treatment of a composite system. Two different subsystem decompositions (symmetric and nonsymmetric) of the linear response function are presented, and the pole structures as well as residues of the individual terms are analyzed and discussed. This theoretical analysis clarifies which form of the response function to use in polarizable embedding, and we highlight complications in separating out subsystem contributions to molecular properties. For example, based on the nonsymmetric decomposition of the complex linear response function, we derive conservation laws for integrated absorption cross sections, providing a solid basis for proper calculations of the intersubsystem intensity borrowing inherent to coupled subsystems and how that can lead to negative subsystem intensities. We finally identify steps and approximations required to achieve the transition from a quantum-mechanical description of the composite system to polarizable embedding with a classical treatment of the environment, thus providing a thorough justification for the descriptions used in polarizable embedding models

The Nonsymmetric Kaluza-Klein(Jordan-Thiry) Theory.A path to a Unified Field Theory

In the paper we consider the Nonsymmetric Kaluza-Klein(Jordan-Thiry) Theory and hierarchy of a symmetry breaking within Grand Unified Theories.In this way we try to construct Unified Field Theory.We conside alsoa quintessence and skewon fields as possible Dark Matter particles.Both particles are massive with zero and one spin.It means with scalar and pseudovector particles.They are interacting only gravitationally..They are really apart of gravity.In this way they are geometrized.We find anatural to get a cosmological constant(Dark Energy) and the fith force. We consider also an effective gravitational" constant" Geff and a test particles movement in the theory.We consider also a tower of scalar (massive) fields as additional Dark Matter derived in the paper.Comment: TeX, 146 pages ,no figures,some corrections and extension

The energy–momentum method for the stability of non-holonomic systems

In this paper we analyze the stability of relative equilibria of nonholonomic systems (that is, mechanical systems with nonintegrable constraints such as rolling constraints). In the absence of external dissipation, such systems conserve energy, but nonetheless can exhibit both neutrally stable and asymptotically stable, as well as linearly unstable relative equilibria. To carry out the stability analysis, we use a generalization of the energy-momentum method combined with the Lyapunov-Malkin theorem and the center manifold theorem. While this approach is consistent with the energy-momentum method for holonomic systems, it extends it in substantial ways. The theory is illustrated with several examples, including the the rolling disk, the roller racer, and the rattleback top