2 citations · 5 across the 6 of their papers we have counts for
6 papers
Which Cubic Graphs have Quadrangulated Spherical Immersions?
Lowell Abrams, Yosef Berman, Vance Faber +1
We consider spherical quadrangulations -- spherical embeddings of multigraphs, possibly with loops, so that every face has boundary walk of length 4 -- in which all vertices have d…
A Basic Structure for Grids in Surfaces
Lowell Abrams, Daniel Slilaty
A graph embedded in a surface is called an -grid when every facial boundary walk has length four, that is, the topological dual graph of in is 4-regular. Aside f…
New Dualities From Old: generating geometric, Petrie, and Wilson dualities and trialites of ribbon graphs
Lowell Abrams, Jo Ellis-Monaghan
We develop an algebraic framework for ribbon graphs, revealing symmetry properties of (partial) twisted duality. The original ribbon group action of Ellis-Monaghan and Moffatt rest…
Cotensor products of modules
Lowell Abrams, Charles Weibel
Let C be a coalgebra over a field k and A its dual algebra. The category of C-comodules is equivalent to a category of A-modules. We use this to interpret the cotensor product M \s…
Modules, comodules and cotensor products over Frobenius algebras
Lowell Abrams
We characterize noncommutative Frobenius algebras A in terms of the existence of a coproduct which is a map of left A^e-modules. We show that the category of right (left) comodules…
The quantum Euler class and the quantum cohomology of the Grassmannians
Lowell Abrams
The Poincare duality of classical cohomology and the extension of this duality to quantum cohomology endows these rings with the structure of a Frobenius algebra. Any such algebra…