Tuesday, November 15, 14:00, 7.527
Gena Puninski (Moscow), Classifying projective modules over semilocal rings.

Abstract:
Classification of (finitely and infinitely generated) projective modules over a given ring is a classical and very difficult problem. In my talk I will discuss a recent progress on classification of projective modules over semilocal rings. It follows from a recent result by Prihoda that such modules can be classified by finite tuples of cardinal numbers (called dimensions).; and the set of all dimension vectors of projective modules (over a given semilocal ring R) is called the spectrum of R. In our talk we will review a recent breakthrough on the description of (projective) spectra of semilocal rings. Some general constructions (due to Herbera and Prihoda) will be mentioned; and certain concrete examples of semilocal rings with `strange projectives' will be discussed.