نتایج جستجو برای: conformally recurrency

تعداد نتایج: 2819  

2004
Misha Verbitsky

A locally conformally Kähler (LCK) manifold M is one which is covered by a Kähler manifold M̃ with the deck transform group acting conformally on M̃ . If M admits a holomorphic flow, acting on M̃ conformally, it is called a Vaisman manifold. Neither the class of LCK manifolds nor that of Vaisman manifolds is stable under small deformations. We define a new class of LCK-manifolds, called LCK manifo...

1996
A. Iorio

Scale-invariant actions in arbitrary dimensions are investigated in curved space to clarify the relation between scale-, Weyland conformal invariance on the classical level. The global Weyl-group is gauged. Then the class of actions is determined for which Weyl-gauging may be replaced by a suitable coupling to the curvature (Ricci gauging). It is shown that this class is exactly the class of ac...

1997
Kevin C. K. Chan

By using the Garfinkle, Horowitz and Strominger black hole solutions as examples, we illustrate that, with respect to the reference action functional proposed by Hawking and Horowitz, the asymp-totic mass parameter is not invariant between two conformally related static spherically symmetric metrics.

2001
Gregg Buskey Gordon Wyeth Jonathan Roberts

This paper details the developments to date of an unmanned air vehicle (UAV) based on a standard size 60 model helicopter. The design goal is to have the helicopter achieve stable hover with the aid of an INS and stereo vision. The focus of this paper is on the development of an artificial neural network (ANN) that makes use of only the INS data to generate hover commands, which are used to dir...

2008
HAO FANG

In this paper, we prove the following two results: First, we study a class of conformally invariant operators P and their related conformally invariant curvatures Q on even-dimensional Riemannian manifolds. When the manifold is locally conformally flat(LCF) and compact without boundary, Q-curvature is naturally related to the integrand in the classical Gauss-Bonnet-Chern formula, i.e., the Pfaf...

2006
Misha Verbitsky

A locally conformally Kähler (LCK) manifold M is one which is covered by a Kähler manifold M̃ with the deck transform group acting conformally on M̃ . If M admits a holomorphic flow, acting on M̃ conformally, it is called a Vaisman manifold. Neither the class of LCK manifolds nor that of Vaisman manifolds is stable under small deformations. We define a new class of LCK-manifolds, called LCK manifo...

Journal: :Physical review. D, Particles and fields 1993
Gegenberg Kunstatter

A solvable 2-dimensional conformally invariant midi-superspace model for black holes is obtained by imposing spherical symmetry in 4-dimensional conformally invariant Einstein gravity. The Wheeler-DeWitt equation for the theory is solved exactly to obtain the unique quantum wave functional for an isolated black hole with fixed mass. By suitably relaxing the boundary conditions, a non-perturbati...

2008
Xianzhe Dai

We define an abelian group, the conformal cobordism group of hyperbolic structures, which classifies the hyperbolic structures according to whether it bounds a (higher dimensional) conformally flat structure in a conformally invariant way. We then construct a homomorphism from this group to the circle group, using the eta invariant. The homomorphism can be highly nontrivial. It remains an inter...

Journal: :Physical review. D, Particles and fields 1994
Tanaka Sasaki

We extend our previous analysis of the quantum state during and after O(4)symmetric bubble nucleation to the case including gravitational effects. We find that there exists a simple relationship between the case with and without gravitational effects. In a special case of a conformally coupled scalar field which is massless except on the bubble wall, the state is found to be conformally equival...

2004
Valerio Faraoni

We study a toy model for phantom cosmology recently introduced in the literature and consisting of two oscillators, one of which carries negative kinetic energy. The results are compared with the exact phase space picture obtained for similar dynamical systems describing, respectively, a massive canonical scalar field conformally coupled to the spacetime curvature, and a conformally coupled mas...

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