Jan Draisma

Strength and partition rank under limits and field extensions

Arthur Bik, Jan Draisma, Amichai Lampert, Tamar Ziegler

Abstract The strength of a multivariate homogeneous polynomial is the minimal number of terms in an expression as a sum of products of lower‐degree homogeneous polynomials. Partition rank is the analogue for multilinear forms. Both ranks can drop under field extensions, and …

us, ch, nl, il (code pays fourni par la source)

A criterion for the algebraic density property of smooth affine SL2-varieties

Rafael B. Andrist, Jan Draisma, Gene Freudenburg, Gaofeng Huang et autres

On the dimensions of correlated equilibrium polytopes of generic games

Jan Draisma, Linda Hoyer, Irem Portakal

In this paper, we study the dimension of the correlated equilibrium polytope of finite games. Under the oriented-matroid notion of genericity, we prove that if a generic game is not full-dimensional, then there exists a subgame whose correlated equilibrium polytope is affinely …

On the dimensions of correlated equilibrium polytopes of generic games

Jan Draisma, Linda Hoyer, Irem Portakal

In this paper, we study the dimension of the correlated equilibrium polytope of finite games. Under the oriented-matroid notion of genericity, we prove that if a generic game is not full-dimensional, then there exists a subgame whose correlated equilibrium polytope is affinely …

The space of preorders on a commutative monoid

Jan Draisma, George Metcalfe, Simon Santschi

For a finitely generated commutative monoid $Π$, we present a constructive description of all (total) preorders on $Π$ that are compatible with the monoid structure. Equipped with a natural topology, these preorders form an irreducible spectral space, which we show can be …

The space of preorders on a commutative monoid

Jan Draisma, George Metcalfe, Simon Santschi

For a finitely generated commutative monoid $Π$, we present a constructive description of all (total) preorders on $Π$ that are compatible with the monoid structure. Equipped with a natural topology, these preorders form an irreducible spectral space, which we show can be …

md, ch (code pays fourni par la source)

Computing the continuous symmetries of a parametrized variety

Benjamin Biaggi, Jan Draisma, Fulvio Gesmundo, Aida Maraj et autres

We prove that the symmetry Lie algebra of a parametrized variety can be determined directly from the parametrization, without computing the vanishing ideal of the variety. We derive a practical polynomial-time Monte Carlo algorithm for computing the symmetry Lie algebra of a …

Computing the continuous symmetries of a parametrized variety

Benjamin Biaggi, Jan Draisma, Fulvio Gesmundo, Aida Maraj et autres

We prove that the symmetry Lie algebra of a parametrized variety can be determined directly from the parametrization, without computing the vanishing ideal of the variety. We derive a practical polynomial-time Monte Carlo algorithm for computing the symmetry Lie algebra of a …

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Binomiality of undirected colored Gaussian graphical models

Benjamin Biaggi, Jan Draisma, Magdaléna Mišinová

Following earlier work by Coons-Maraj-Misra-Sorea and Misra-Sullivant, we study colored, undirected Gaussian graphical models, and present a necessary and sufficient condition for such a model to have binomial vanishing ideal. These conditions involve Jordan schemes, a variant of association schemes, well-known structures …

ch, de (code pays fourni par la source)

Binomiality of undirected colored Gaussian graphical models

Benjamin Biaggi, Jan Draisma, Magdaléna Mišinová

ch, de (code pays fourni par la source)

Improved unirationality for GL-varieties

Arthur Bik, Jan Draisma, Rob Eggermont, Andrew W. Snowden

A $\mathbf{GL}$-variety is a typically infinite dimensional variety equipped with a suitable action of the infinite general linear group $\mathbf{GL}$. In earlier work, we established the unirationality theorem: an irreducible $\mathbf{GL}$-variety admits a dominant map from a particularly simple $\mathbf{GL}$-variety, namely, the …

Improved unirationality for GL-varieties

Arthur Bik, Jan Draisma, Rob Eggermont, Andrew W. Snowden

A $\mathbf{GL}$-variety is a typically infinite dimensional variety equipped with a suitable action of the infinite general linear group $\mathbf{GL}$. In earlier work, we established the unirationality theorem: an irreducible $\mathbf{GL}$-variety admits a dominant map from a particularly simple $\mathbf{GL}$-variety, namely, the …