43 citations · 69 across the 5 of their papers we have counts for
7 papers
A proof of a cyclic version of Deligne's conjecture via Cacti
Ralph M. Kaufmann
In this note, we show that the normalized Hochschild co--chains of an associative algebra with a non--degenerate, symmetric, invariant inner product are an algebra over a chain mod…
Singularities with Symmetries, orbifold Frobenius algebras and Mirror Symmetry
Ralph M. Kaufmann
Previously, we introduced a duality transformation for Euler --Frobenius algebras. Using this transformation, we prove that the simple singularities and Pham singulariti…
On Spineless Cacti, Deligne's Conjecture and Connes--Kreimer's Hopf Algebra
Ralph M. Kaufmann
Using a cell model for the little discs operad in terms of spineless cacti we give a minimal common topological operadic formalism for three a priori disparate algebraic structures…
Pointed Admissible G-Covers and G-equivariant Cohomological Field Theories
Tyler J. Jarvis, Ralph Kaufmann, Takashi Kimura
For any finite group G we define the moduli space of pointed admissible G-covers and the concept of a G-equivariant cohomological field theory (G-CohFT), which, when G is the trivi…
The algebra of discrete torsion
Ralph M. Kaufmann
We analyze the algebraic structures of G--Frobenius algebras which are the algebras associated to global group quotient objects. Here G is any finite group. These algebras turn out…
Orbifolding Frobenius Algebras
Ralph M. Kaufmann
We study the general theory of Frobenius algebras with group actions. These structures arise when one is studying the algebraic structures associated to a geometry stemming from a…