The rst law of black hole mechanics (in the form derived by Wald), is expressed in terms of integrals over surfaces, at the horizon and spatial in nity, of a stationary, axisymmetric black hole, in a di eomorphism invariant Lagrangian theory of gravity. The original statement of the rst law given by Bardeen, Carter and Hawking for an Einstein-perfect uid system contained, in addition, volume in...

The first law of black hole mechanics (in the form derived by Wald), is expressed in terms of integrals over surfaces, at the horizon and spatial infinity, of a stationary, axisymmetric black hole, in a diffeomorphism invariant Lagrangian theory of gravity. The original statement of the first law given by Bardeen, Carter and Hawking for an Einstein-perfect fluid system contained, in addition, v...

We generalize the optical geometry to include, not only conformally static spacetimes, but any spacetime that admits a hypersurface orthogonal shearless congruence of worldlines. In the generalized optical geometry, which in general is time dependent, photons move with constant speed along spatial geodesics. Gyroscopes moving along spatial geodesics do not precess. We also classify inertial for...

We report measurements of the transient multimode dynamics of vertical cavity surface emitting lasers excited by short ~100–200 ps rise times, 1 ns duration! electrical pulses. Fast changes on the spatial distribution of the output power and strong mode competition are observed. Numerical simulations show that the observed dynamics are due to the partial overlap of the different transverse mode...

using piezoelectric patches the stress concentration around a hole on a plate under tension is reduced and controlled. to attain the reduction in stress two placements for piezoelectric patches is investigated. the first location is top/bottom of the hole with compression induced strain and the second is left/right of the hole with tension induced strains to control the stress flow. the result ...

because of production process and constrains conditions, circular graphene sheet may be opposed to structural defect and pin hole, respectively. some of the defects and pin hole on a circular graphene sheet can be considered as an eccentric hole on the sheet. hence, analyzing behavior of circular graphene sheet with an eccentric hole is important. free vibration of an eccentric annular graphene...

Finite temperature hole dynamics in the t−J model: exact results for high dimensions PACS. 71.10.Fd – Lattice fermion models (Hubbard model, etc.). Abstract. – We discuss the dynamics of a single hole in the t−J model at finite temperature, in the limit of large spatial dimensions. The problem is shown to yield a simple and physically transparent solution, that exemplifies the continuous therma...

Parallel and converging hole collimators are most frequently used in nuclear medicine. Less common is the use of rotating slat collimators for single photon emission computed tomography (SPECT). The higher photon collection efficiency, inherent to the geometry of rotating slat collimators, results in much lower noise in the data. However, plane integrals contain spatial information in only one ...

Motivated by the recently proposed Kerr/CFT correspondence, we investigate the holographic dual of the extremal and non-extremal rotating linear dilaton black hole in Einstein-Maxwell-Dilaton-Axion Gravity. For the case of extremal black hole, by imposing the appropriate boundary condition at spatial infinity of the near horizon extremal geometry, the Virasoro algebra of conserved charges assoc...