The Poincare mass operator in terms of a hyperbolic algebra

The Poincare mass operator can be represented in terms of a Cl(3,0) Clifford algebra. With this representation the quadratic Dirac equation and the Maxwell equations can be derived from the same mathematical structure.Comment: 5 pages Latex2

Testimony Traces in Appellate Review: Expertise Extension in Cases of Domestic Abuse and Eyewitness Identification

Appellate rulings contribute to policy deliberations on uses of and parameters for expert testimony. As courts perform gatekeeping and evaluative roles, opinions highlight investigative independence, calculations of probability, and consistency across studies. Even so, the elements from expert testimony most commonly extended into precedent stand out for their summative concision and figurative cogency

CFT description of three-dimensional Kerr-de Sitter spacetime

We describe three-dimensional Kerr-de Sitter space using similar methods as recently applied to the BTZ black hole. A rigorous form of the classical connection between gravity in three dimensions and two-dimensional conformal field theory is employed, where the fundamental degrees of freedom are described in terms of two dependent SL(2,C) currents. In contrast to the BTZ case, however, quantization does not give the Bekenstein-Hawking entropy connected to the cosmological horizon of Kerr-de Sitter space.Comment: 12 pages, v2: references added and some structural change

Topological and conformal field theory as Frobenius algebras

Two-dimensional conformal field theory (CFT) can be defined through its correlation functions. These must satisfy certain consistency conditions which arise from the cutting of world sheets along circles or intervals. The construction of a (rational) CFT can be divided into two steps, of which one is complex-analytic and one purely algebraic. We realise the algebraic part of the construction with the help of three-dimensional topological field theory and show that any symmetric special Frobenius algebra in the appropriate braided monoidal category gives rise to a solution. A special class of examples is provided by two-dimensional topological field theories, for which the relevant monoidal category is the category of vector spaces.Comment: 23 pages, several figures, proceedings to the Streetfest (Canberra 07/2005); v2: section 2.4 expanded, version accepted for publication in Contemp. Mat