On the arithmetical rank of a special class of minimal varieties (Q1005899)

Let \(I\subset A\) be a proper ideal in a noetherian ring, a hard problem consist to determine the minimal number (\(\mathrm{ara}(I)\)) of generators of \(I\) up to radical, this invariant is related to the cohomological dimension. In this paper the author studies the arithmetical rank and the cohomological dimensions of an infinite class of Cohen-Macaulay varieties of minimal degree. Among these the author finds infinitely many set-theoretic complete intersections. The author gives examples where the arithmetical rank is arbitrarily greater than the codimension. Reviewer's remark: I should say that Lemma 7 in this paper is known to many people working in this subject and appears in a paper published before.