Homepage of Lars Kastner


Lars Kastner

I am a research assistant at the Free University in Berlin.

Office: Arnimallee 3, Room 115
e-mail: kastner[at]domain
where domain = math[dot]fu[minus]berlin[dot]de

Research interests

My main research interest lies at the intersection of Combinatorics with Algebraic Geometry and Commutative algebra. I wrote my thesis in the area of toric geometry and commutative algebra. Furthermore I like tropical geometry and T-varieties, i.e. varieties with an action by a lower dimensional torus.

A major part of my work involves developing and implementing algorithms for the problems I encounter. I mainly use the systems Macaulay2, polymake and Singular. This allows computing many examples in very short time for developing and checking conjectures.


Ext and Tor on two-dimensional cyclic quotient singularities (2016, to be found on the arXiv)
Thesis: Ext on affine toric varieties (published 2016, available online at Freie Universität)
A Web Application for Macaulay2, with Franziska Hinkelmann and Michael Stillman (2015, to be found online at github)
Negative deformations of toric singularities that are smooth in codimension two, with Klaus Altmann (2013, appeared in Deformations of surface singularities, Bolyai Mathematical Society, to be found on the arXiv)
Calculating Generators of Multigraded Algebras, with Nathan Ilten (2013, appeared in Journal of Symbolic Computation, to be found on the arXiv)


My github username is   lkastner.
Computer algebra system developed by Michael Stillman and Daniel Grayson. I am currently one of the maintainers of the ‘Polyhedra’ package for computations involving polyhedral objects.
Software framework for computations involving polyhedral objects. Together with Benjamin Lorenz I am author of the application ideal for interfacing Singular, as well as of the application fulton for toric geometry.
Computer algebra system developed by Gert-Marting Greuel and Gerhard Pfister. I am a co-author of the library multigrading.lib for computations involving multigraded rings.