We give the explicite form of the BRST charge Q for the algebra W4 = WA3 in the basis where the spin-3 and the spin-4 field are primary as well as for a basis where the algebra closes quadratically. ∗e-mail: [email protected]; 31890::HORNFECK For the construction of W-strings [1], especially its physical states, it is important to know the cohomology of the BRST charge [2, 3, 4, 5, 6, 7, 8, 9...

A computable structure A is decidable if, given a formula φ(x̄) of elementary first-order logic, and a tuple ā ∈ A, we have a decision procedure to decide whether φ holds of ā. We show that there is no reasonable classification of the decidably presentable structures. Formally, we show that the index set of the computable structures with decidable presentations is Σ1-complete. This result holds ...

Abstract. We construct a Wilson action for the Wess-Zumino model by applying the exact renormalization group perturbatively. Using neither superfields nor auxiliary fields, we construct a supersymmetric action only with complex scalar and Majorana spinor fields. We adopt the BRST (antifield) formalism to show the consistency of the construction to all orders in loop expansions. The resulting ac...

For -continuous endofunctors of Set an ordering of a final coalgebra is exhibited which makes a CPO. Moreover, an initial algebra, considered as a canonical subobject of , has as its ideal completion. In more generality, for -continuous endofunctors of locally finitely presentable categories the analogous result holds: here the ordering is considered on the hom-sets for all finitely presentable...

We develop a homotopy theory of categories enriched in a monoidal model category V. In particular, we deal with homotopy weighted limits and colimits, and homotopy local presentability. The main result, which was known for simplicially-enriched categories, links homotopy locally presentable V-categories with combinatorial model V-categories, in the case where all objects of V are cofibrant.

This write-up starts by introducing lattice chirality to people possessing a fairly modern mathematical background, but little prior knowledge about modern physics. I then proceed to present two new and speculative ideas. 1.1 What are Dirac/Weyl fermions ? One can think about (Euclidean) Field Theory as of an attempt to define integrals over function spaces [1]. The functions are of different t...