The total energy--momentum tensor for electromagnetic fields in a dielectric

There are various formulations of energy--momentum tensors for an electromagnetic field in a linear dielectric. The total energy--momentum tensor, comprised of electromagnetic and material components, must be unique. We discuss the construction of the total energy--momentum tensor and the associated conservation laws.Comment: Added publication informatio

Is Entanglement Sufficient to Enable Quantum Speedup?

According to the Gottesman-Knill theorem, any quantum algorithm utilising operations chosen exclusively from a particular restricted set are efficiently simulable by a classical computer. Since some of these algorithms involve entangled states, it is commonly concluded that entanglement is insufficient to enable quantum speedup. As I explain, however, the operations belonging to this set are precisely those which will never yield a violation of the Bell inequalities. Thus it should be no surprise that entangled quantum states which only undergo operations in this set are efficiently simulable classically. What the Gottesman-Knill theorem shows us is that it is possible to use an entangled state to less than its full potential. Nevertheless, there is a meaningful sense in which entanglement is sufficient for quantum speedup: an entangled quantum state provides sufficient physical resources to enable quantum speedup, whether or not one elects to use these resources fully.Comment: Only minor changes from last version. Comments and criticisms are welcome. This article has been superseded by arXiv:1310.093

Foreword: Waiver of Constitutional Rights: Disquiet in the Citadel

Foreword to Harvard Law Review review of Supreme Court 1969 Ter