%0 Journal Article %T Non-rationality of a three-dimensional Fano variety of index 2 and degree 1 %A Mikhail Grinenko %J Mathematics %D 2003 %I arXiv %X We describe the set of Mori structures for a Fano 3-fold of index 2 and degree 1 (the double cone over the Veronese surface). In partiular, it is proved that such a Fano variety is not rational, the group of birational automorphisms coincides with the group of biregular automorphisms, and there are no structures of conic bundle. %U http://arxiv.org/abs/math/0304321v1