Classical energy-momentum tensor renormalization via effective field theory methods

Renormalization of the energy-momentum tensor in noncommutative complex scalar field theory

We study the renormalization of dimension four composite operators and the energy-momentum tensor in noncommutative complex scalar field theory. The proper operator basis is defined and it is proved that the bare composite operators are expressed via renormalized ones with the help of an appropriate mixing matrix which is calculated in the one-loop approximation. The number and form of the oper...

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...

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...

Renormalization and Effective Field Theory

The renormalization of the energy-momentum tensor for an effective initial state

An effective description of an initial state is a method for representing the signatures of new physics in the short-distance structure of a quantum state. The expectation value of the energy-momentum tensor for a field in such a state contains new divergences that arise when summing over this new structure. These divergences occur only at the initial time at which the state is defined and ther...