Conformal Contact Terms and Semi-local Terms

`-derived Schemes and Local Terms

This paper is a continuation of our study of local terms and independence of ` begun in [16, 17] and continuing in subsequent papers. Let k be an algebraically closed field and let ` be a prime invertible in k. Let E denote either a finite extension of Q` or an algebraic closure Q`. Recall that if c : C → X × X is a correspondence of quasi-projective schemes over k, and if F ∈ D c(X,E) is a com...

Contact Terms, Symmetries and D-Instantons

The scattering of NS ⊗ NS antisymmetric tensor states in the presence of D-instantons in type IIB superstring theory is studied. It is shown that in order to preserve gauge invari-ance, spacetime supersymmetry and picture changing symmetry the inclusion of boundary contact terms for closed string antisymmetric tensor vertex operators is necessary.

World-Sheet Supersymmetry Without Contact Terms

Green and Seiberg showed that, in simple treatments of fermionic string theory, it is necessary to introduce contact interactions when vertex operators collide. Otherwise, certain superconformal Ward identities would be violated. In this note, we show how these contact terms arise naturally when proper account is taken of the superconformal geometry involved when punctures collide. More precise...

Sheaves on Curves and Their Local Terms

Anomalies, Local Counter Terms and Bosonization

We re-examine the issue of local counter terms in the analysis of quantum anomalies. We analyze two-dimensional theories and show that the notion of local counter terms need to be carefully defined depending on the physics contents such as whether one is analyzing gauge theory or bosonization. It is shown that a part of the Jacobian, which is apparently spurious and eliminated by a local counte...