Geometric Properties of the Double-Point Divisor
| dc.creator | Ilic, Bo | |
| dc.date | 1995-03-17 | |
| dc.date.accessioned | 2026-07-07T09:06:24Z | |
| dc.date.available | 2026-07-07T09:06:24Z | |
| dc.description | Let $X^n \subset P^N$ be a nonsingular, nondegenerate projective variety of dimension $n$ and codimension $N-n \ge 2$. Let $|C_X|$ be the linear system determined by the double-point divisor obtained by generically projecting $X$ to a hypersurface in $P^{n+1}$. We classify those varieties for which $C_X$ is not ample, or equivalently, does not separate points of $X$. We call such varieties Roth varieties and prove that they exist for all dimensions $n \ge 2$ and give a description of their properties. For example, in many cases Roth varieties are Castelnuovo varieties. Positivity results for the double-point divisor are analogous to positivity results for the ramification divisor which are studied in adjunction theory. | |
| dc.description | 31 pages. AMSTeX with amsppt | |
| dc.identifier | https://arxiv.org/abs/alg-geom/9503009 | |
| dc.identifier | http://arxiv.org/abs/alg-geom/9503009 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/149993 | |
| dc.subject | Algebraic Geometry | |
| dc.title | Geometric Properties of the Double-Point Divisor | |
| dc.type | text |