### Positive semigroups in lattices and totally real number fields (Lenny Fukshansky, CMC)

Davidson Lecture Hall, CMC 340 E 9th St, Claremont, CALet L be a full-rank lattice in R^n and write L+ for the semigroup of all vectors with nonnegative coordinates in L. We call a basis X for L positive if it is contained in L+. There are infinitely many such bases, and each of them spans a conical semigroup S(X) consisting of all nonnegative […]