176 citations · 343 across the 44 of their papers we have counts for
49 papers
Non-general type surfaces in P4, an update
Hirotachi Abo, Kristian Ranestad, Frank-Olaf Schreyer
A general algebraic surface cannot be embedded in P4. Proving a conjecture by Hartshorne and Lichtenbaum, Ellingsrud and Peskine showed that there is a degree bound for smooth rati…
Minimal Non-Weierstrass Semigroups
David Eisenbud, Frank-Olaf Schreyer
Let p in X be a point on a compact Riemann surface. The Weierstrass semigroup of p is the semigroup of pole orders of meromorphic functions on X that are regular at all but p. Hurw…
Commutative Algebra and Algebraic Geometry using OSCAR
Janko Boehm, Wolfram Decker, Frank-Olaf Schreyer
We give illustrative examples of how the computer algebra system OSCAR can support research in commutative algebra and algebraic geometry. We start with a thorough introduction to…
Extensions and paracanonical curves of genus 6
Frank-Olaf Schreyer, Hoang Le Truong
In this note we give a computationally easy to use method to compute a maximal extension of certain varieties. As a application we prove that a general paracanonical curve C genus…
The variety of polar simplices II
Joachim Jelisiejew, Kristian Ranestad, Frank-Olaf Schreyer
We discuss the space of ideals with Hilbert function that are apolar to a full rank quadric . We prove that its components of saturated ideals are…
Hyperelliptic curves and Ulrich sheaves on the complete intersection of two quadrics
David Eisenbud, Frank-Olaf Schreyer
Using the connection between hyperelliptic curves, Clifford algebras, and complete intersections of two quadrics, we describe Ulrich bundles on and construct some of minima…