Adela Vraciu,
Tight Closure in Cubical Cone Rings


We explore some propeties of tight closure in cubical cone rings, and the connection with Frobenius closure (when the characteristic is congruent to 2 mod 3). We introduce the special tight closure of an ideal, and show (for a certain class of rings, containing the cubical cones) that tight closure is the sum of the special tight closure and the ideal itself.