## Geometric properties of the double-point divisor

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- by Bo Ilic
- Trans. Amer. Math. Soc.
**350**(1998), 1643-1661 - DOI: https://doi.org/10.1090/S0002-9947-98-01928-X
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## Abstract:

The locus of double points obtained by projecting a variety $X^{n} \subset \mathbf {P}^N$ to a hypersurface in $\mathbf {P}^{n+1}$ moves in a linear system which is shown to be ample if and only if $X$ is not an isomorphic projection of a Roth variety. Such Roth varieties are shown to exist, and some of their geometric properties are determined.## References

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## Bibliographic Information

**Bo Ilic**- Affiliation: Department of Mathematics, Columbia University, New York, New York 10027
- Address at time of publication: Department of Mathematics, University of California, Los Angeles, California 90024
- Email: ilic@math.ucla.edu
- Received by editor(s): July 20, 1996
- © Copyright 1998 American Mathematical Society
- Journal: Trans. Amer. Math. Soc.
**350**(1998), 1643-1661 - MSC (1991): Primary 14N05, 14C20, 14J40
- DOI: https://doi.org/10.1090/S0002-9947-98-01928-X
- MathSciNet review: 1422899