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BEGIN:VEVENT
SUMMARY:Rosa Winter (Leiden University)
DTSTART:20200414T150000Z
DTEND:20200414T153000Z
DTSTAMP:20260422T212724Z
UID:NASO/1
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/1/">Rat
 ional points on del Pezzo surfaces of degree 1</a>\nby Rosa Winter (Leiden
  University) as part of Max Planck Institute nonlinear algebra seminar onl
 ine\n\n\nAbstract\nDel Pezzo surfaces are classified by their degree\, an 
 integer between 1 and 9. Famous examples are those of degree 3\, which are
  cubic surfaces in 𝑃3. In this talk I will focus on del Pezzo surfaces 
 of degree 1. After briefly describing their geometry\, I will talk about t
 he set of Q-valued (rational) points on such a surface. I will show what i
 s known about this set so far\, and which questions are still open.\n
LOCATION:https://researchseminars.org/talk/NASO/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yulia Alexandr (University of California at Berkeley)
DTSTART:20200414T154000Z
DTEND:20200414T161000Z
DTSTAMP:20260422T212724Z
UID:NASO/2
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/2/">Log
 arithmic Voronoi cells</a>\nby Yulia Alexandr (University of California at
  Berkeley) as part of Max Planck Institute nonlinear algebra seminar onlin
 e\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Balazs Szendroi (University of Oxford)
DTSTART:20200414T162000Z
DTEND:20200414T165000Z
DTSTAMP:20260422T212724Z
UID:NASO/3
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/3/">The
  punctual Hilbert scheme of 4 points in affine 3-space</a>\nby Balazs Szen
 droi (University of Oxford) as part of Max Planck Institute nonlinear alge
 bra seminar online\n\n\nAbstract\nThe $n$-th punctual Hilbert scheme $\\op
 eratorname{Hilb}^n_0(\\mathbb{A}^d)$ of points of affine $d$-space paramet
 rises ideals of finite co-length $n$ of the ring of functions on $d$-dimen
 sional affine space\, whose radical is the maximal ideal at the origin (eq
 uivalently\, subschemes of length $n$ with support at the origin). A class
 ical theorem of Briancon claims the irreducibility of this space for $d=2$
  and arbitrary $n$. The case of a small number of points being straightfor
 ward\, the first nontrivial case is the case of $4$ points in $3$-space. W
 e show\, answering a question of Sturmfels\, that over the complex numbers
  $\\operatorname{Hilb}^4_0(\\mathbb{A}^3)$ is irreducible. We use a combin
 ation of arguments from computer algebra and representation theory.\n
LOCATION:https://researchseminars.org/talk/NASO/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lisa Nicklasson (Stockholm University)
DTSTART:20200416T150000Z
DTEND:20200416T153000Z
DTSTAMP:20260422T212724Z
UID:NASO/4
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/4/">Sub
 algebras of a polynomial ring with minimal Hilbert function</a>\nby Lisa N
 icklasson (Stockholm University) as part of Max Planck Institute nonlinear
  algebra seminar online\n\n\nAbstract\nIn a recent paper by Boij and Conca
  the upper and lower bounds for the Hilbert function of subalgebras of a p
 olynomial ring are discussed. In this talk we will study subalgebras gener
 ated in degree two with minimal Hilbert function. These subalgebras are ge
 nerated by strongly stable sets of monomials. To minimize the Hilbert func
 tion we want to firstly minimize the numbers of variables\, and secondly t
 he multiplicity of the algebra. This boils down to a purely combinatorial 
 problem\, as the multiplicity can be computed by counting the number of ma
 ximal north-east lattice paths in an diagram representing the strongly sta
 ble set.\n
LOCATION:https://researchseminars.org/talk/NASO/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tara Fife (Louisiana State University)
DTSTART:20200416T154000Z
DTEND:20200416T161000Z
DTSTAMP:20260422T212724Z
UID:NASO/5
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/5/">A f
 riendly Introduction to matroids</a>\nby Tara Fife (Louisiana State Univer
 sity) as part of Max Planck Institute nonlinear algebra seminar online\n\n
 \nAbstract\nMatroids were introduced by Whitney in 1935 to provide an abst
 ract generalization of the notion of linear independence. Whitney noted th
 at matroids arise naturally from graphs and from matrices. More recently\,
  people have discovered ties to matroid theory and algebraic geometry. In 
 this talk\, I will first introduce matroid theory\, along with some key ex
 amples\, and central questions. I will then discuss connections between ma
 troid theory and nonlinear algebra.\n
LOCATION:https://researchseminars.org/talk/NASO/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:José Samper (MPI MIS\, Leipzig)
DTSTART:20200416T162000Z
DTEND:20200416T165000Z
DTSTAMP:20260422T212724Z
UID:NASO/6
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/6/">Som
 e shelling orders are better than others</a>\nby José Samper (MPI MIS\, L
 eipzig) as part of Max Planck Institute nonlinear algebra seminar online\n
 \n\nAbstract\nA shelling order is a recursive way of constructing a polyhe
 dral complex that helps to understand several topological\, algebraic and 
 combinatorial invariants. Consequently\, a significant amount of effort ha
 s been put into developing techniques to determine if a given complex has 
 a shelling order. In this talk we will explore a different point of view t
 hat is less popular: for a complex that admits many shelling orders\, a go
 od choice of the shelling order can can make a significant difference. We 
 address this problem for matroid independence complexes\, present an intri
 guing connection with shelling orders of polytopes\, and discuss some expe
 riments aimed at better understanding some old problems. This is based on 
 joint work Alex Heaton.\n
LOCATION:https://researchseminars.org/talk/NASO/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anna Seigal (University of Oxford)
DTSTART:20200421T150000Z
DTEND:20200421T153000Z
DTSTAMP:20260422T212724Z
UID:NASO/7
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/7/">Tor
 us actions and maximum likelihood estimation</a>\nby Anna Seigal (Universi
 ty of Oxford) as part of Max Planck Institute nonlinear algebra seminar on
 line\n\n\nAbstract\nWe describe connections between invariant theory and m
 aximum likelihood estimation\, in the context of log-linear models. Findin
 g a maximum likelihood estimate (MLE) is an optimisation problem over a st
 atistical model\, to obtain the point that best fits observed data. We sho
 w that this is equivalent to a capacity problem - finding the point of min
 imal norm in an orbit under a corresponding torus action. The existence of
  the MLE can then be characterized by stability under the action. Moreover
 \, algorithms from statistics can be used in invariant theory\, and vice v
 ersa. Based on joint work with Carlos Améndola\, Kathlén Kohn and Philip
 p Reichenbach. This is part one of a two part talk: in the second part\, P
 hilipp Reichenbach will discuss our results for multivariate Gaussian mode
 ls.\n
LOCATION:https://researchseminars.org/talk/NASO/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Philipp Reichenbach (Technical University Berlin)
DTSTART:20200421T154000Z
DTEND:20200421T161000Z
DTSTAMP:20260422T212724Z
UID:NASO/8
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/8/">Inv
 ariant Theory and Matrix Normal Models</a>\nby Philipp Reichenbach (Techni
 cal University Berlin) as part of Max Planck Institute nonlinear algebra s
 eminar online\n\n\nAbstract\nWe describe connections between invariant the
 ory and maximum likelihood estimation (ML estimation)\, in the context of 
 matrix normal models. Namely\, we link ML estimation in that case to the l
 eft right action of SLxSL on tuples of matrices. This enables us to charac
 terize ML estimation by stability under that group action. Furthermore\, i
 nvariant theory provides a new upper bound on the sample size for generic 
 boundedness of the log-likelihood function. To illuminate the theory the t
 alk puts emphasis on several examples. At the end we briefly outline how o
 ur results generalize to Gaussian group models.\n\nBased on joint work wit
 h Carlos Améndola\, Kathlén Kohn and Anna Seigal. This is the second par
 t of a two part talk: in the first part\, Anna Seigal will discuss our res
 ults for log-linear models.\n
LOCATION:https://researchseminars.org/talk/NASO/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aida Maraj (University of Kentucky)
DTSTART:20200421T162000Z
DTEND:20200421T165000Z
DTSTAMP:20260422T212724Z
UID:NASO/9
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/9/">The
  Equivariant Hilbert Series of Hierarchical Models</a>\nby Aida Maraj (Uni
 versity of Kentucky) as part of Max Planck Institute nonlinear algebra sem
 inar online\n\n\nAbstract\nA hierarchical model is realizable by a simplic
 ial complex that describes the dependency relationships among random varia
 bles and the number of states of each random variable. Diaconis and Sturmf
 els have constructed toric ideals that provide useful information about th
 e model. This talk concerns quantitative properties for families of ideals
  arising from hierarchical models with the same dependency relations and v
 arying number of states. We introduce and study invariant filtrations of s
 uch ideals\, and their equivariant Hilbert series. A condition that guaran
 tees this multivariate series is a rational function will be presented. Th
 e key is to construct finite automata that recognize languages correspondi
 ng to invariant filtrations. Lastly\, we show that one can similarly prove
  the rationality of an equivariant Hilbert series for some filtrations of 
 algebras. This is joint work with Uwe Nagel.\n
LOCATION:https://researchseminars.org/talk/NASO/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michael Ruddy (MPI MIS\, Leipzig)
DTSTART:20200423T150000Z
DTEND:20200423T153000Z
DTSTAMP:20260422T212724Z
UID:NASO/10
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/10/">Eq
 uivalence classes of planar algebraic curves through numerical algebraic g
 eometry</a>\nby Michael Ruddy (MPI MIS\, Leipzig) as part of Max Planck In
 stitute nonlinear algebra seminar online\n\n\nAbstract\nFor the action of 
 a group on the plane\, the group equivalence problem for curves can be sta
 ted as: given two curves\, decide if they are related by an element of the
  group. We describe an efficient equality test\, using tools from numerica
 l algebraic geometry\, to determine (with “probability-one”) whether o
 r not two rational maps have the same image up to Zariski closure. Using s
 ignature maps\, constructed from differential and joint invariants\, we ap
 ply this test to solve the group equivalence problem for algebraic curves 
 under the linear action of algebraic groups. In this talk I will discuss t
 he equality test and signature maps for algebraic curves\, focusing on the
  action of the complex Euclidean group for our computations and examples. 
 I will present some of our results comparing the sensitivity of different 
 signature maps. This is based on joint work with Tim Duff.\n
LOCATION:https://researchseminars.org/talk/NASO/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Laura Brustenga i Moncusi (University of Copenhagen)
DTSTART:20200423T154000Z
DTEND:20200423T161000Z
DTSTAMP:20260422T212724Z
UID:NASO/11
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/11/">Re
 action networks and toric systems</a>\nby Laura Brustenga i Moncusi (Unive
 rsity of Copenhagen) as part of Max Planck Institute nonlinear algebra sem
 inar online\n\n\nAbstract\nMass-action networks (edge labelled directed gr
 aphs) model cascades of chemical reactions (e.g. used by biological system
 s for adapting to the environment). From the assumption of mass-action kin
 etics\, a mass-action network gives rise to a polynomial dynamical system.
  In this large class of polynomial systems\, the intuition from Chemistry 
 and Algebraic Geometry feed themselves\, giving exciting new results. For 
 example\, we will discuss complex balanced mass-action networks\, which ha
 ve a natural chemical interpretation and (conjecturally) completely determ
 ines the dynamics of the associated systems (called toric dynamical system
 s). We will introduce “disguised toric systems”\, which exploit this r
 elationship the other way around: given a dynamical system\, can we build 
 a complex balanced mass-action network for it?\n\n(Joint work with Gheorgh
 e Craciun and Miruna-Ştefana Sorea).\n
LOCATION:https://researchseminars.org/talk/NASO/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Taylor Brysiewicz (Texas A&M)
DTSTART:20200423T162000Z
DTEND:20200423T165000Z
DTSTAMP:20260422T212724Z
UID:NASO/12
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/12/">So
 lving decomposable sparse systems</a>\nby Taylor Brysiewicz (Texas A&M) as
  part of Max Planck Institute nonlinear algebra seminar online\n\n\nAbstra
 ct\nAmendola et al. proposed a method for solving systems of polynomial eq
 uations lying in a family which exploits a recursive decomposition into sm
 aller systems. A family of systems admits such a decomposition if and only
  if the corresponding monodromy group is imprimitive. A consequence of Est
 erov’s classification of sparse polynomial systems with imprimitive mono
 dromy groups is that this decomposition is obtained by inspection. Using t
 hese ideas\, we present a recursive algorithm to numerically solve decompo
 sable sparse systems. This is joint work with Frank Sottile\, Jose Rodrigu
 ez\, and Thomas Yahl.\n
LOCATION:https://researchseminars.org/talk/NASO/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sascha Timme (Technical University Berlin)
DTSTART:20200430T150000Z
DTEND:20200430T153000Z
DTSTAMP:20260422T212724Z
UID:NASO/13
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/13/">32
 64 Conics in a Second</a>\nby Sascha Timme (Technical University Berlin) a
 s part of Max Planck Institute nonlinear algebra seminar online\n\n\nAbstr
 act\nEnumerative algebraic geometry counts the solutions to certain geomet
 ric constraints. Numerical algebraic geometry determines these solutions f
 or any given instance. In this talk I want to illustrate how these two fie
 lds complement each other. The focus lies on the 3264 conics that are tang
 ent to five given conics in the plane. I will illustrate tools and techniq
 ues used in numerical algebraic geometry and how we used these to find a f
 ully real instance of this classic problem.\n\nThis is joint work with P. 
 Breiding and B. Sturmfels.\n
LOCATION:https://researchseminars.org/talk/NASO/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Louis Theran (University of St. Andrews)
DTSTART:20200409T154000Z
DTEND:20200409T162000Z
DTSTAMP:20260422T212724Z
UID:NASO/14
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/14/">Gr
 aph rigidity and measurement varieties</a>\nby Louis Theran (University of
  St. Andrews) as part of Max Planck Institute nonlinear algebra seminar on
 line\n\n\nAbstract\nGeometric rigidity theory is concerned with how much i
 nformation about a configuration p of n points in a d-dimensional Euclidea
 n space is determined by pairwise Euclidean distance measurements\, indexe
 d by the edges of a graph G with n vertices. One can turn this around\, an
 d\, define\, for a fixed graph G\, a “measurement variety" associated wi
 th all possible edge lengths measurements as the configuration varies. I
 ’ll survey some (somewhat) recent results in geometric rigidity obtained
  by studying the geometry of measurement varieties.\n
LOCATION:https://researchseminars.org/talk/NASO/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eugenie Hunsicker (Loughborough University)
DTSTART:20200409T162000Z
DTEND:20200409T170000Z
DTSTAMP:20260422T212724Z
UID:NASO/15
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/15/">Ar
 chitecture for the Working Mathematician</a>\nby Eugenie Hunsicker (Loughb
 orough University) as part of Max Planck Institute nonlinear algebra semin
 ar online\n\n\nAbstract\nDel Pezzo surfaces are classified by their degree
 \, an integer between 1 and 9. Famous examples are those of degree 3\, whi
 ch are cubic surfaces in $P ^ 3$. In this talk I will focus on del Pezzo s
 urfaces of degree 1. After briefly describing their geometry\, I will talk
  about the set of Q-valued (rational) points on such a surface. I will sho
 w what is known about this set so far\, and which questions are still open
 .\n
LOCATION:https://researchseminars.org/talk/NASO/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joscha Diehl (Universität Greifswald)
DTSTART:20200428T150000Z
DTEND:20200428T153000Z
DTSTAMP:20260422T212724Z
UID:NASO/16
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/16/">Ti
 me warping invariants and quasisymmetric functions</a>\nby Joscha Diehl (U
 niversität Greifswald) as part of Max Planck Institute nonlinear algebra 
 seminar online\n\n\nAbstract\nThe analysis of time series is a standard ta
 sk in data science. Usually\, as a first step\, features of a time series 
 must be extracted that characterize the series\, maybe modulo irrelevant (
 depending on the application) group actions on the original data. In this 
 talk I will discuss the action of time-warping: the features should be inv
 ariant to the speed at which the time-series is run through. This leads\, 
 as we show\, to quasisymmetric functions\, and I discuss their Hopf algebr
 aic setup.\n
LOCATION:https://researchseminars.org/talk/NASO/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Arthur Bik (Universität Bern)
DTSTART:20200428T154000Z
DTEND:20200428T161000Z
DTSTAMP:20260422T212724Z
UID:NASO/17
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/17/">Po
 lynomial functors as affine spaces</a>\nby Arthur Bik (Universität Bern) 
 as part of Max Planck Institute nonlinear algebra seminar online\n\n\nAbst
 ract\nPolynomial functors are like spaces of objects (e.g. k-way tensors) 
 without fixed size and come with an action of (products of) general linear
  groups. The aim of this talk is to answer the following question: what ha
 ppens when you replace vector spaces by polynomial functors when defining 
 affine spaces?\n\nI will define polynomial functors\, the maps between the
 m and their Zariski-closed subsets and give examples of these things. Then
 \, I will discuss how to extend some of the basic results from affine alge
 braic geometry to this setting. This is joint work with Jan Draisma\, Rob 
 Eggermont and Andrew Snowden.\n
LOCATION:https://researchseminars.org/talk/NASO/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lukas Kühne (The Hebrew University of Jerusalem)
DTSTART:20200428T162000Z
DTEND:20200428T165000Z
DTSTAMP:20260422T212724Z
UID:NASO/18
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/18/">Ge
 neralised Matroid Representations: Universality and Decidability</a>\nby L
 ukas Kühne (The Hebrew University of Jerusalem) as part of Max Planck Ins
 titute nonlinear algebra seminar online\n\n\nAbstract\nA matroid is a comb
 inatorial object based on an abstraction of linear independence in vector 
 spaces and forests in graphs. It is a classical question to determine whet
 her a given matroid is representable as a vector configuration over a fiel
 d. Such a matroid is called linear.\n\nThis talk addresses generalisations
  of such representations over division rings or matrix rings which are cal
 led skew linear and multilinear matroids respectively.We will describe a g
 eneralised Dowling geometry that encodes non commutative equations in matr
 oids. This construction allows us to reduce word problem instances to skew
  linear or multilinear matroid representations.\n\nThe talk is based on jo
 int work with Rudi Pendavingh and Geva Yashfe.\n
LOCATION:https://researchseminars.org/talk/NASO/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Frank Sottile (Texas A&M University)
DTSTART:20200430T154000Z
DTEND:20200430T161000Z
DTSTAMP:20260422T212724Z
UID:NASO/19
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/19/">Ga
 lois groups in Enumerative Geometry and Applications</a>\nby Frank Sottile
  (Texas A&M University) as part of Max Planck Institute nonlinear algebra 
 seminar online\n\n\nAbstract\nIn 1870 Jordan explained how Galois theory c
 an be applied to problems from enumerative geometry\, with the group encod
 ing intrinsic structure of the problem. Earlier Hermite showed the equival
 ence of Galois groups with geometric monodromy groups\, and in 1979 Harris
  initiated the modern study of Galois groups of enumerative problems. He p
 osited that a Galois group should be ‘as large as possible’ in that it
  will be the largest group preserving internal symmetry in the geometric p
 roblem.\n\nI will describe this background and discuss some work in a long
 -term project to compute\, study\, and use Galois groups of geometric prob
 lems\, including those that arise in applications of algebraic geometry. A
  main focus is to understand Galois groups in the Schubert calculus\, a we
 ll-understood class of geometric problems that has long served as a labora
 tory for testing new ideas in enumerative geometry.\n
LOCATION:https://researchseminars.org/talk/NASO/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Khazhgali Kozhasov (Technical University Braunschweig)
DTSTART:20200430T162000Z
DTEND:20200430T165000Z
DTSTAMP:20260422T212724Z
UID:NASO/20
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/20/">On
  Minimality of Determinantal Varieties</a>\nby Khazhgali Kozhasov (Technic
 al University Braunschweig) as part of Max Planck Institute nonlinear alge
 bra seminar online\n\n\nAbstract\nMinimal submanifolds are mathematical ab
 stractions of soap films: they minimize the Riemannian volume locally arou
 nd every point. Finding minimal algebraic hypersurfaces in 𝑅𝑛 for ea
 ch n is a long-standing open problem posed by Hsiang. In 2010 Tkachev gave
  a partial solution to this problem showing that the hypersurface of n x n
  real matrices of corank one is minimal. I will discuss the following gene
 ralization of this fact to all determinantal matrix varieties: for any m\,
  n and r<m\,n the (open) variety of m x n real matrices of rank r is minim
 al.\n
LOCATION:https://researchseminars.org/talk/NASO/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Diane Maclagan (University of Warwick)
DTSTART:20200512T150000Z
DTEND:20200512T160000Z
DTSTAMP:20260422T212724Z
UID:NASO/21
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/21/">Co
 nnectivity of tropical varieties</a>\nby Diane Maclagan (University of War
 wick) as part of Max Planck Institute nonlinear algebra seminar online\n\n
 Abstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joachim Jelisiejew (University of Warsaw)
DTSTART:20200519T150000Z
DTEND:20200519T160000Z
DTSTAMP:20260422T212724Z
UID:NASO/22
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/22/">Ad
 ditive group actions\, formal solutions to PDEs and Bialynicki-Birula deco
 mposition</a>\nby Joachim Jelisiejew (University of Warsaw) as part of Max
  Planck Institute nonlinear algebra seminar online\n\n\nAbstract\nLet $X$ 
 be a smooth projective variety over $\\mathbb{C}$ with an action of $(\\ma
 thbb{C}\, +)$. Assume that $X$ has a unique fixed point $x_0$. Carrell’s
  conjecture predicts that $X$ is rational. Restriction of orbits to germs 
 at $x_0$ reduces this conjecture to describing solutions of certain system
 s of PDE in the formal power series ring $k[[t]]$ with $d(t) = -t^2$. This
  suggests a stronger form of the conjecture: $X$ is a union of affine spac
 es. This strengthening would give an analogue of Bialynicki-Birula decompo
 sition for $(\\mathbb{C}\, +)$.\nIn the talk I will explain the beautiful 
 basics on how the $(\\mathbb{C}\, +)$-actions\, differential equations and
  rationality intertwine and then present the state of the art on the conje
 cture. This is a work in progress\, comments and suggestions are welcome!\
 n
LOCATION:https://researchseminars.org/talk/NASO/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Christian Ikenmeyer (University of Liverpool)
DTSTART:20200526T150000Z
DTEND:20200526T160000Z
DTSTAMP:20260422T212724Z
UID:NASO/23
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/23/">Gr
 oup varieties of polynomials and computational complexity</a>\nby Christia
 n Ikenmeyer (University of Liverpool) as part of Max Planck Institute nonl
 inear algebra seminar online\n\n\nAbstract\nMany varieties of polynomials 
 carry a canonical action of the general linear group. This talk gives an i
 ntroduction on how representation theory can be used in the study of the e
 quations of such varieties. We then focus on recent research in geometric 
 complexity theory on continuant orbit closures and plethysm coefficients.\
 n
LOCATION:https://researchseminars.org/talk/NASO/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Laurent Manivel (Paul Sabatier University)
DTSTART:20200616T150000Z
DTEND:20200616T160000Z
DTSTAMP:20260422T212724Z
UID:NASO/24
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/24/">Or
 bital Degeneracy Loci</a>\nby Laurent Manivel (Paul Sabatier University) a
 s part of Max Planck Institute nonlinear algebra seminar online\n\nAbstrac
 t: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tim Seynnaeve (Max Planck Institute for Mathematics in the Science
 s)
DTSTART:20200602T150000Z
DTEND:20200602T160000Z
DTSTAMP:20260422T212724Z
UID:NASO/25
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/25/">Co
 mplete quadrics and algebraic statistics</a>\nby Tim Seynnaeve (Max Planck
  Institute for Mathematics in the Sciences) as part of Max Planck Institut
 e nonlinear algebra seminar online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alessandra Bernardi (Università di Trento)
DTSTART:20200609T150000Z
DTEND:20200609T160000Z
DTSTAMP:20260422T212724Z
UID:NASO/26
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/26/">Al
 gorithms for polynomial decompositions</a>\nby Alessandra Bernardi (Univer
 sità di Trento) as part of Max Planck Institute nonlinear algebra seminar
  online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Amy Huang (Texas A&M University)
DTSTART:20200623T150000Z
DTEND:20200623T155000Z
DTSTAMP:20260422T212724Z
UID:NASO/27
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/27/">Va
 nishing Hessian and Wild Polynomials</a>\nby Amy Huang (Texas A&M Universi
 ty) as part of Max Planck Institute nonlinear algebra seminar online\n\nAb
 stract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Henrik Eisenmann (Max Planck Institute for Mathematics in the Scie
 nces)
DTSTART:20200630T150000Z
DTEND:20200630T155000Z
DTSTAMP:20260422T212724Z
UID:NASO/28
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/28/">Us
 ing an alternating approach to solve two-parameter eigenvalue problems</a>
 \nby Henrik Eisenmann (Max Planck Institute for Mathematics in the Science
 s) as part of Max Planck Institute nonlinear algebra seminar online\n\nAbs
 tract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rosa Winter (Max Planck Institute for Mathematics in the Sciences)
DTSTART:20210202T160000Z
DTEND:20210202T164500Z
DTSTAMP:20260422T212724Z
UID:NASO/29
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/29/">Li
 near spaces of symmetric matrices with non-maximal maximum likelihood degr
 ee</a>\nby Rosa Winter (Max Planck Institute for Mathematics in the Scienc
 es) as part of Max Planck Institute nonlinear algebra seminar online\n\nAb
 stract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Juliette Bruce (University of California\, Berkeley)
DTSTART:20210202T164500Z
DTEND:20210202T173000Z
DTSTAMP:20260422T212724Z
UID:NASO/30
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/30/">Th
 e top weight cohomology of Ag</a>\nby Juliette Bruce (University of Califo
 rnia\, Berkeley) as part of Max Planck Institute nonlinear algebra seminar
  online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Luca Sodomaco (Aalto University)
DTSTART:20210216T160000Z
DTEND:20210216T164500Z
DTSTAMP:20260422T212724Z
UID:NASO/31
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/31/">As
 ymptotics of degrees and ED degrees of Segre products</a>\nby Luca Sodomac
 o (Aalto University) as part of Max Planck Institute nonlinear algebra sem
 inar online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Elizabeth Gross (University of Hawai`i at Mānoa)
DTSTART:20210216T164500Z
DTEND:20210216T173000Z
DTSTAMP:20260422T212724Z
UID:NASO/32
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/32/">Wh
 en do two networks have the same steady-state ideal?</a>\nby Elizabeth Gro
 ss (University of Hawai`i at Mānoa) as part of Max Planck Institute nonli
 near algebra seminar online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aldo Conca (Università di Genova)
DTSTART:20210223T160000Z
DTEND:20210223T164500Z
DTSTAMP:20260422T212724Z
UID:NASO/33
DESCRIPTION:by Aldo Conca (Università di Genova) as part of Max Planck In
 stitute nonlinear algebra seminar online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mauricio Velasco (Universidad de los Andes\, Bogotá)
DTSTART:20210223T164500Z
DTEND:20210223T173000Z
DTSTAMP:20260422T212724Z
UID:NASO/34
DESCRIPTION:by Mauricio Velasco (Universidad de los Andes\, Bogotá) as pa
 rt of Max Planck Institute nonlinear algebra seminar online\n\nAbstract: T
 BA\n
LOCATION:https://researchseminars.org/talk/NASO/34/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gleb Pogudin (École polytechnique Paris)
DTSTART:20210302T160000Z
DTEND:20210302T164500Z
DTSTAMP:20260422T212724Z
UID:NASO/35
DESCRIPTION:by Gleb Pogudin (École polytechnique Paris) as part of Max Pl
 anck Institute nonlinear algebra seminar online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/35/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alicia Dickenstein (Universidad de Buenos Aires)
DTSTART:20210302T164500Z
DTEND:20210302T173000Z
DTSTAMP:20260422T212724Z
UID:NASO/36
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/36/">Op
 timal Descartes rule of signs for polynomial systems supported on circuits
 </a>\nby Alicia Dickenstein (Universidad de Buenos Aires) as part of Max P
 lanck Institute nonlinear algebra seminar online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/36/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Liam Solus (KTH Royal Institute of Technology)
DTSTART:20210316T160000Z
DTEND:20210316T164500Z
DTSTAMP:20260422T212724Z
UID:NASO/38
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/38/">So
 me recent developments on the geometry of causation</a>\nby Liam Solus (KT
 H Royal Institute of Technology) as part of Max Planck Institute nonlinear
  algebra seminar online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/38/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lisa Nicklasson (Max Planck Institute for Mathematics in the Scien
 ces)
DTSTART:20210316T164500Z
DTEND:20210316T173000Z
DTSTAMP:20260422T212724Z
UID:NASO/39
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/39/">To
 ric ideals of polymatroids and White’s conjecture</a>\nby Lisa Nicklasso
 n (Max Planck Institute for Mathematics in the Sciences) as part of Max Pl
 anck Institute nonlinear algebra seminar online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/39/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Georg Regensburger (Johannes Kepler Universität Linz)
DTSTART:20210330T150000Z
DTEND:20210330T154500Z
DTSTAMP:20260422T212724Z
UID:NASO/40
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/40/">Po
 sitive solutions of generalized polynomial systems with real exponents and
  chemical reaction networks</a>\nby Georg Regensburger (Johannes Kepler Un
 iversität Linz) as part of Max Planck Institute nonlinear algebra seminar
  online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/40/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jonas Hirsch (Leipzig University)
DTSTART:20210330T154500Z
DTEND:20210330T163000Z
DTSTAMP:20260422T212724Z
UID:NASO/41
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/41/">Re
 al varieties and measure-valued solutions to PDEs</a>\nby Jonas Hirsch (Le
 ipzig University) as part of Max Planck Institute nonlinear algebra semina
 r online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/41/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anna-Laura Sattelberger (MPI MiS)
DTSTART:20220221T133000Z
DTEND:20220221T135500Z
DTSTAMP:20260422T212724Z
UID:NASO/42
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/42/">Li
 near Differential Operators in the Sciences</a>\nby Anna-Laura Sattelberge
 r (MPI MiS) as part of Max Planck Institute nonlinear algebra seminar onli
 ne\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/42/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eliana Duarte (Centro de Matemática of the Universidade do Porto)
DTSTART:20220221T135500Z
DTEND:20220221T142000Z
DTSTAMP:20260422T212724Z
UID:NASO/43
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/43/">To
 ric Varieties in Algebraic Statistics and Geometric Modeling</a>\nby Elian
 a Duarte (Centro de Matemática of the Universidade do Porto) as part of M
 ax Planck Institute nonlinear algebra seminar online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/43/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fulvio Gesmundo (MP MiS)
DTSTART:20220221T142000Z
DTEND:20220221T144500Z
DTSTAMP:20260422T212724Z
UID:NASO/44
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/44/">Ge
 ometric methods in the study of tensor networks</a>\nby Fulvio Gesmundo (M
 P MiS) as part of Max Planck Institute nonlinear algebra seminar online\n\
 nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/44/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Giles Gardam (University of Muenster)
DTSTART:20220221T144500Z
DTEND:20220221T151000Z
DTSTAMP:20260422T212724Z
UID:NASO/45
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/45/">Th
 e Kaplansky conjectures</a>\nby Giles Gardam (University of Muenster) as p
 art of Max Planck Institute nonlinear algebra seminar online\n\nAbstract: 
 TBA\n
LOCATION:https://researchseminars.org/talk/NASO/45/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marta Panizzut (TU Berlin)
DTSTART:20220221T152000Z
DTEND:20220221T154500Z
DTSTAMP:20260422T212724Z
UID:NASO/46
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/46/">Co
 mputational methods in polyhedral and algebraic geometry</a>\nby Marta Pan
 izzut (TU Berlin) as part of Max Planck Institute nonlinear algebra semina
 r online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/46/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marvin Anas Hahn (Sorbonne Université)
DTSTART:20220221T154500Z
DTEND:20220221T161000Z
DTSTAMP:20260422T212724Z
UID:NASO/47
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/47/">De
 generations in algebraic and applied geometry</a>\nby Marvin Anas Hahn (So
 rbonne Université) as part of Max Planck Institute nonlinear algebra semi
 nar online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/47/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simon Telen (MPI MiS)
DTSTART:20220221T161000Z
DTEND:20220221T163500Z
DTSTAMP:20260422T212724Z
UID:NASO/48
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/48/">Nu
 merical nonlinear algebra in particle physics</a>\nby Simon Telen (MPI MiS
 ) as part of Max Planck Institute nonlinear algebra seminar online\n\nAbst
 ract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/48/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yairon Cid Ruiz (Ghent University)
DTSTART:20220221T163500Z
DTEND:20220221T170000Z
DTSTAMP:20260422T212724Z
UID:NASO/49
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NASO/49/">Mu
 ltidegrees at the crossroads of algebra\, geometry and combinatorics</a>\n
 by Yairon Cid Ruiz (Ghent University) as part of Max Planck Institute nonl
 inear algebra seminar online\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/NASO/49/
END:VEVENT
END:VCALENDAR
