| Home | Registration | Programme | Logistics | Organisation |
| 8:00 - 8:45 | Registration |
| 8:45 - 9:00 | Opening Remarks |
| Organizing Committee | |
| 9:00-10:00 | Plenary 1: Tropical Graph Embeddings |
| Josef Schicho (Johannes Kepler University Linz, Austria) | |
AbstractLet \(G=(V,E)\) be a simple, undirected graph without self-loops and let \(\lambda\in\mathbb R^{E}\) be a labeling of edges by real numbers. A planar framework of \((G,\lambda)\) is a function \(\rho\) mapping \(V\) into the plane such that the squared Euclidean distance between vertices connected by an edge is equal to the label of that edge. If we say the plane is \(\mathbb R^2\), and the squared distance is given by a nondegenerate quadratic form, then the set of planar frameworks is an algebraic variety. For generic labeling, its dimension is \(2|V|-|E|\), if not empty.The group \(\mathrm{SE}_2\) of Euclidean displacements acts on the variety of frameworks. To choose representatives, we pass to "pinned frameworks", which have one edge fixed. The dimension drops then by \(3\) to \(2|V|-|E|-3\). In this talk, we will ask several questions about the algebraic variety of pinned frameworks, in dimension 0 and 1, and try to answer them by tropical geometry. With tropical geometry, one can take an algebraic variety and "tropicalise" it, obtaining a piecewise linear object that reflects some properties of the algebraic variety. Instead of costly algebraic computations, we will answer our questions by faster combinatoric algorithms. |
| 10:00-10:30 | Coffee Break |
| 10:30-12:00 | Parallel Session 1 | |
| Computational and Effective Commutative Algebra | Real Projective Geometry and Grassmannian | |
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The SagbiHomotopy.jl package for solving polynomial systems Numerical Algebraic Geometry for Energy Computations on Tensor Train Varieties A priori bounds for certified Krawczyk homotopy tracking |
Condition-based Low-Degree Approximation of Real Polynomial Systems. II.W: The Positive Dimensional Case in the Elliptic Regime Varieties of Lines in 3-Space The Self-Projecting Grassmannian |
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| 12:00-14:00 | Lunch |
| 14:00-15:00 | Plenary 2: Symmetric Ideals |
| Alexandra Seceleanu (University of Nebraska-Lincoln. USA) | |
AbstractAn ideal in a polynomial ring is called symmetric if it is invariant as a set under the action of the symmetric group, which permutes variables. This talk explores two classes of symmetric ideals: those reflecting the typical behavior of a randomly chosen symmetric ideal, and those enriched with strong combinatorial structure arising from the Borel group.In the first part, motivated by the principle that a general member in a family often exhibits desirable properties, we develop a framework for defining and studying general symmetric ideals with a fixed number of generators up to symmetry. This perspective reveals interesting homological stability phenomena. In the second part, focusing on symmetric ideals generated by monomials, we introduce the notion of symmetric strongly sifted ideals—the symmetrizations of strongly stable ideals from commutative algebra. We present structural, homological, and combinatorial results for the former ideals, highlighting their connections to discrete polymatroids and permutohedral toric varieties. This talk is based on joint work with Megumi Harada and Liana Sega, as well as separate collaborations with Liana Sega and Alessandra Costantini. |
| 15:00-15:30 | Coffee Break |
| 15:30-17:00 | Parallel Session 2 | |
| Computational and Effective Commutative Algebra | Real Projective Geometry and Grassmannian | |
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Homogeneous Khovanskii bases and MUVAK bases The Gröbner basis for powers of a general linear form in a monomial complete intersection Gröbner bases native to term-ordered commutative algebras, with application to the Hodge algebra of minors |
Quadrature rules with few nodes supported on algebraic curves Geometry of Adjoint Hypersurfaces for Polytopes On the effective Pourchet's Theorem |
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| 9:00-10:00 | Plenary 3: On strongly robust toric ideals |
| Dimitra Kosta (University of Edinburgh, UK) | |
AbstractA toric ideal is called strongly robust when its minimal system of generators coincides with its Graver basis. In the talk, I will explain how using the bouquet structure one can build a strongly robust simplicial complex which determines the strongly robust property of toric ideals. This turns Sullivant's question about the structure of the bouquets of strongly robust toric ideals, into a question about the dimension of the strongly robust simplicial complex. I will then discuss our results on the strongly robust property which include the case of monomial curves, codimension 2 toric ideals and configurations in general position. This is joint work with A. Thoma and M. Vladoiu. |
| 10:00-10:30 | Coffee Break |
| 10:30-12:00 | Parallel Session 3 | |
| Algebraic Statistics, Models, Identifiability | Positivity, Real Algebraic Geometry, Polynomial Optimization | |
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Maximum likelihood thresholds vs generic completion rank in colored gaussian graphical models Identifiability in Non-Gaussian Discrete Lyapunov Models MLdegrees of 3D polytopes with MLdegree one faces |
Toric Extensions of Pólya's Theorem Copositivity, discriminants and nonseparable signed supports Certificates for nonnegativity of multivariate integer polynomials under perturbations |
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| 12:00-14:00 | Lunch |
| 14:00-15:00 | Plenary 4: On the distance to singular hypersurfaces |
| Khazhgali Kozhasov (Université Côte d'Azur, France) | |
AbstractThe Euclidean Distance degree of an affine (real) algebraic variety X is (an upper bound on) the number of (real) critical points of the Euclidean distance to X from a generic (real) point u. However, if X is singular, a minimizer might belong to the singular locus of X for a positive-dimensional set of inputs u and thus it is natural to study the Euclidean distance to Sing(X). I will discuss this phenomenon for the discriminant X=D consisting of degree d (real) homogeneous polynomials with (real) singular points, where the ambient space is endowed with the Bombieri (also known as Fubini-Study) Euclidean structure. I will present a formula for the ED degree of the component of Sing(D) that contains polynomials with cuspidal singularities. This, together with the known formula for the ED degree of D, gives a measure of algebraic complexity of the distance minimization problem to D. The talk is based on a joint work with B. Mourrain and A. Parusiński. |
| 15:00-15:30 | Coffee Break |
| 15:30-17:10 | Software presentations | |
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Drawing real plane algebraic curves in OSCAR Signature Tensors in OSCAR The ShowProof command in GeoGebra: automated ranking and derivation of geometric statements ProjectedHypersurfaceRegions.jl: Computing Complements of Real Hypersurfaces Using Pseudo-Witness Sets Computer-Assisted Discovery and Proofs of Compatibility Conditions for Three Projective Cameras |
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| 17:10-20:00 | Poster Session |
| 9:00-10:00 | Plenary 5 (title tba) |
| Anna Seigal (Harvard University, USA) | |
| 10:00-10:30 | Coffee Break |
| 10:30-12:00 | Parallel Session 4 | |
| Tensor Decompositions and Ranks | Applied Algebraic Geometry, Dynamical Systems Signatures | |
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A refinement on the local cactus rank algorithm Generalized Additive Decompositions of Symmetric Tensors Chisel-based tensor decomposition |
Lissajous Varieties Path signatures of ODE solutions Nonlinear Kalman varieties |
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| 12:00- | Free Afternoon |
| 9:00-10:00 | Plenary 6: Vertically parametrized systems and the generic geometry of steady state varieties of reaction networks |
| Elisenda Feliu (University of Copenhagen, Denmark) | |
AbstractThe mathematical theory of chemical and biochemical reaction networks traces its origins to the pioneering work of Feinberg, Horn, and Jackson in the 1970s. Despite substantial progress, several fundamental questions concerning the positive steady states of reaction networks remain open. These steady states are described by a parametric polynomial system with a special structure known as a "vertically parametrized system". Recent advances have revealed a rich geometric framework for vertically parametrized systems, extending many classical results for sparse (or freely parametrized) polynomial systems with fixed support.In this talk, I will present some of these developments and highlight their implications for reaction network theory. Among the topics discussed will be generic finiteness and nondegeneracy of steady states, toric structures, absolute concentration robustness, and the nondegenerate multistationarity conjecture. This is joint work with Oskar Henriksson and Beatriz Pascual Escudero. |
| 10:00-10:30 | Coffee Break |
| 10:30-12:00 | Parallel Session 5 | |
| Statistics, Models, Applications | Combinatoric and Toric Algebra | |
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Singular Learning Theory for Factor Analysis Computing The Continuous Symmetries of a Parametrized Variety Proof of a Conjecture of Drton, Sturmfels and Sullivant on the maximum likelihood degree of the Gaussian graphical model of a cycle |
Dilworth truncations and Hadamard products of linear spaces Minuscule Coxeter Dressians A new bound on the rank of tensor product of W-states |
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| 12:00-14:00 | Lunch |
| 14:00-15:00 | Plenary 7: Polynomial Constraint Extraction Techniques in the Graphical Models Program |
| Liam Solus (KTH Royal Institute of Technology, Sweden) | |
AbstractApplied algebra is driven in large part by the realization that many models for real data can be viewed as semialgebraic sets parameterized via a rational map. An important example are graphical models, which provide a flexible framework for developing statistical inference techniques for multivariate data. Since data comes in many shapes and sizes, different graphical model families are needed for different data problems, and each family requires its own basic mathematical theory to support inference. In this context, general techniques for recovering implicit (polynomial) constraints satisfied by semialgebraic sets translate into tools for developing the basic theory of graphical model families. In this talk, we will discuss the connection between the graphical models program and the research program in applied algebra centered on extracting polynomial constraints satisfied by parametrized semialgebraic sets. Special attention will be given to some recent polynomial constraint extraction techniques that offer solutions in the graphical models program where no non-algebraic solution exists. |
| 15:00-15:30 | Coffee Break |
| 15:30-17:00 | Parallel Session 6 | |
| Statistics, Models, Applications | Combinatoric and Toric Algebra | |
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Avoidance Loci of Real Projective Varieties Polynomials of small slice rank and strength Webs on pointwise sums of two rational curves |
A linear-time algorithm for Chow decompositions The Symmetric Hilbert Series Castelnuovo-Mumford regularity of toric varieties with at most one singular point |
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| 17:30-19:00 | Board Meeting |
| The board meeting is private. Only members of the advisory board and explicitely invited partipants may participate. |
| 19:00- | Evening social @ Gray College Bar |
| 9:00-10:00 | Plenary 8: Algebraic geometry and integer lattices |
| Tommy Hofmann (University of Siegen, Germany) | |
| 10:00-10:30 | Coffee Break |
| 10:30-12:00 | Parallel Session 7 | |
| Effective Computation, Algorithms, Software | Tensors, Complexity, Quantum-type Applications | |
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Effective computation of Gromov-Witten invariants for GKM spaces Algorithms to Calculate Invariant Rings of Finite Group Schemes Nongeneral-type surfaces in projective four-space: a package for Macaulay2 |
Computing moment polytopes of tensors and polynomials Neural Learning of Fast Matrix Multiplication Algorithms: A StrassenNet Approach The Coupled Cluster Doubles Truncation Variety of Four Electrons |
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| 12:00-14:00 | Lunch |
| 14:00-15:00 | Plenary 9 (title tba) |
| Michael Walter (LMU Munich, Germany) | |