Energy-momentum tensor of the M-theory fivebrane

M Theory Fivebrane and Sqcd

Positivity and the Energy Momentum Tensor in Quantum Field Theory

The applicability of the weak energy condition in flat space quantum field theory to expectation values of the the energy momentum tensor is reconsidered. It is shown how the usual counter arguments against the validity of any positivity condition fail if the states |ψ〉 are restricted to a suitably defined subspace. A possible natural restriction on |ψ〉 is suggested and illustrated by two quant...

Nonconservation of energy-momentum tensor in classical Liouville theory

where Ah is the area of the horizon. In this context, the classical Liouville theory [4] has gained considerable importance owing to the work of Solodukhin [5]. He showed that the computation of the black hole entropy can be carried out at the classical level. He observed that the 4-dimensional Einstein-Hilbert action can be reduced to an effective 2-dimensional theory, with fixed boundary cond...

Addendum: Symmetries of the energy-momentum tensor

In recent papers [1-3], we have discussed matter symmetries of non-static spherically symmetric spacetimes, static plane symmetric spacetimes and cylindrically symmetric static spacetimes. These have been classified for both cases when the energy-momentum tensor is non-degenerate and also when it is degenerate. Here we add up some consequences and the missing references about the Ricci tensor. ...

Energy-Momentum tensor on foliations

In this paper, we give a new lower bound for the eigenvalues of the Dirac operator on a compact spin manifold. This estimate is motivated by the fact that in its limiting case a skew-symmetric tensor (see Equation (1.6)) appears that can be identified geometrically with the O’Neill tensor of a Riemannian flow, carrying a transversal parallel spinor. The Heisenberg group which is a fibration ove...