Search results for "Map"
showing 10 items of 3484 documents
Birkhoff theorem and conformal Killing-Yano tensors
2015
We analyze the main geometric conditions imposed by the hypothesis of the Jebsen-Birkhoff theorem. We show that the result (existence of an additional Killing vector) does not necessarily require a three-dimensional isometry group on two-dimensional orbits but only the existence of a conformal Killing-Yano tensor. In this approach the (additional) isometry appears as the known invariant Killing vector that the ${\cal D}$-metrics admit.
Anomalies from nonfree action of the gauge group
1990
Abstract The question whether new anomalies appear, connected with the finite dimensional part of the gauge group isomorphic to the structure group of the theory, is investigated in a systematical way. The stability groups from the stratification of the gauge group on the space of connections lead to anomalies. The detection of these anomalies within the equivariant approach pursued here is extremely simple. For a large class of theories it is shown that no new anomalies appear.
Lacunary Bifurcation of Multiple Solutions of Nonlinear Eigenvalue Problems
1991
In order to describe the type of nonlinear eigenvalue problems we are going to discuss, consider a densely defined closed linear operator T in a real Hilbert space H and let H1 be the Hilbert space which consists of the domain of T together with the graph norm. Also, let H 1 * be the dual space of H1 and denote the dual operator corresponding to T: H1 → H by T’:H → H 1 * . Since H1 is dense in H, we may view H as a subspace of H1, and then the scalar product (·,·) on H and the dual pairing on H1 × H 1 * coincide on H1 × H.
Dijet azimuthal correlations and conditional yields in pp and p+Pb collisions at sNN=5.02TeV with the ATLAS detector
2019
This paper presents a measurement of forward-forward and forward-central dijet azimuthal angular correlations and conditional yields in proton-proton (pp) and proton-lead (p + Pb) collisions as a p ...
Equivariance in topological gravity
1992
Abstract We present models of topological gravity for a variety of moduli space conditions. In four dimensions, we construct a model for self-dual gravity characterized by the moduli condition R + μν =0, and in two dimensions we treat the case of constant scalar curvature. Details are also given for both flat and Yang-Mills type moduli conditions in arbitrary dimensions. All models are based on the same fundamental multiplet which conveniently affords the construction of a complete hierarchy of observables. This approach is founded on a symmetry algebra which includes a local vector supersymmetry, in addition to a global BRST-like symmetry which is equivariant with respect to Lorentz transf…
Dynamical Aspects of Generalized Palatini Theories of Gravity
2009
We study the field equations of modified theories of gravity in which the Lagrangian is a general function of the Ricci scalar and Ricci-squared terms in Palatini formalism. We show that the independent connection can be expressed as the Levi-Civitagrave connection of an auxiliary metric which, in particular cases of interest, is related with the physical metric by means of a disformal transformation. This relation between physical and auxiliary metric boils down to a conformal transformation in the case of f(R) theories. We also show with explicit models that the inclusion of Ricci-squared terms in the action can impose upper bounds on the accessible values of pressure and density, which m…
Mathematical Issues in a Fully-Constrained Formulation of Einstein Equations
2008
Bonazzola, Gourgoulhon, Grandcl\'ement, and Novak [Phys. Rev. D {\bf 70}, 104007 (2004)] proposed a new formulation for 3+1 numerical relativity. Einstein equations result, according to that formalism, in a coupled elliptic-hyperbolic system. We have carried out a preliminary analysis of the mathematical structure of that system, in particular focusing on the equations governing the evolution for the deviation of a conformal metric from a flat fiducial one. The choice of a Dirac's gauge for the spatial coordinates guarantees the mathematical characterization of that system as a (strongly) hyperbolic system of conservation laws. In the presence of boundaries, this characterization also depen…
Improved constrained scheme for the Einstein equations: An approach to the uniqueness issue
2008
Uniqueness problems in the elliptic sector of constrained formulations of Einstein equations have a dramatic effect on the physical validity of some numerical solutions, for instance when calculating the spacetime of very compact stars or nascent black holes. The fully constrained formulation (FCF) proposed by Bonazzola, Gourgoulhon, Grandcl\'ement, and Novak is one of these formulations. It contains, as a particular case, the approximation of the conformal flatness condition (CFC) which, in the last ten years, has been used in many astrophysical applications. The elliptic part of the FCF basically shares the same differential operators as the elliptic equations in CFC scheme. We present he…
extended MSSM
2012
We investigate the perturbative regime of the Minimal Supersymmetric Con- formal Technicolor and show that it allows for a stable vacuum correctly breaking the electroweak symmetry. We nd that the particle spectrum is richer than the MSSM one since it features several new particles stemming out from the new N = 4 sector of the theory. The parameter space of the new theory is reduced imposing naturalness of the cou- plings and soft supersymmetry breaking masses, perturbativity of the model at the EW scale as well as phenomenological constraints. By studying the RGEs at two loops we nd that the Yukawa couplings of the heavy fermionic states
Particles and energy fluxes from a conformal field theory perspective
2004
We analyze the creation of particles in two dimensions under the action of conformal transformations. We focus our attention on Mobius transformations and compare the usual approach, based on the Bogoliubov coefficients, with an alternative but equivalent viewpoint based on correlation functions. In the latter approach the absence of particle production under full Mobius transformations is manifest. Moreover, we give examples, using the moving-mirror analogy, to illustrate the close relation between the production of quanta and energy.