TOPICS
Search

Nagata-Biran-Szemberg Conjecture


The qualitative Nagata-Biran-Szemberg conjecture asserts that multipoint Seshadri constants of a fixed polarized variety attain their volume upper bound at sufficiently many very general points. For a smooth integral complex projective variety X of dimension n>=2 with ample line bundle L, it asks for an integer r_0(X,L) such that

 epsilon(X,L;p)=(L^n/r)^(1/n)

at very general distinct tuples for every integer r>=r_0(X,L). The surface form is also called the qualitative Nagata-Biran conjecture. It asks for exact equality at each sufficiently large point count, rather than an asymptotic ratio.

For the projective plane the Nagata conjecture makes the sharper prediction starting at ten points, including a strict degree-multiplicity inequality.


See also

Nagata Conjecture, Nef Divisor, Seshadri Constant

Explore with Wolfram|Alpha

References

Roé, J. and Ross, J. "An Inequality Between Multipoint Seshadri Constants." Geom. Dedicata 140, 175-181, 2009. https://doi.org/10.1007/s10711-008-9315-4.

Cite this as:

Weisstein, Eric W. "Nagata-Biran-Szemberg Conjecture." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Nagata-Biran-SzembergConjecture.html

Subject classifications