Vanishing cotangent cohomology for Plücker algebras

We use representation theory and Bott’s theorem to show vanishing of higher cotangent cohomology modules for the homogeneous coordinate ring of Grassmannians in the Plücker embedding. As a by-product, we answer a question of Wahl about the cohomology of the square of the ideal sheaf for the case of Plücker relations. We obtain slightly weaker vanishing results for the cotangent cohomology of the coordinate rings of isotropic Grassmannians.     

线性子空间关系运算的Plücker坐标表示

本文讨论了线性子空间Plücker的线性表示,给出了Plücker关系式的矩阵形式,并由之导出了子空间关联关系、零化子空间、和子空间与交子空间Plücker坐标的矩阵表达式.     

On orthogonality-preserving plücker transformations of hyperbolic spaces

A complete overview of all orthogonality-preserving Plücker transformations in finite dimensional hyperbolic spaces with dimension other than three is given. In the Cayley-Klein model of such a hyperbolic space all Plücker transformations are induced by collineations of the ambient projective space.     

Differential geometry of grassmannians and the Plücker map

Using the Plücker map between grassmannians, we study basic aspects of classic grassmannian geometries. For ‘hyperbolic’ grassmannian geometries, we prove some facts (for instance, that the Plücker map is a minimal isometric embedding) that were previously known in the ‘elliptic’ case.     

A note on Gröbner bases

In this paper we introduce the new notion of co-polynomials as polynomials arising from the Graßmann–Plücker polynomials. Pairs of co-polynomials are shown to be critical in the computation of a Gröbner basis for the chirotope ideal.     

Harmonic mappings and hyperbolic Plücker transformations

Let be a 3-dimensional hyperbolic space with Euclidean ground field . There is a certain procedure by which any harmonic mapping of the projective line over the unique quadratic extension of induces an orthogonality-preserving Plücker transformation of and, conversely, any orthogonality-preserving Plücker transformation of is induced by such a harmonic mapping. Received 30 July 1999; revised 25 November 1999.     

Symmetric functions,codes of partitions and the KP hierarchy

We consider an operator of Bernstein for symmetric functions and give an explicit formula for its action on an arbitrary Schur function. This formula is given in a remarkably simple form when written in terms of some notation based on the code of a partition. As an application, we give a new and very simple proof of a classical result for the KP hierarchy, which involves the Plücker relations for Schur function coefficients in a τ-function for the hierarchy. This proof is especially compact because we are able to restate the Plücker relations in a form that is symmetrical in terms of partition code notation.     

Closed form of inverse Plücker correspondence in line geometry

Science China Mathematics - By mapping the homogeneous coordinates of two points in space to the Plücker coordinates of the line they determine, any transformation of type SL(4) upon points in...     

Mathematical models as artefacts for research: Felix Klein and the case of Kummer surfaces

Already as a student in Bonn, Felix Klein was exposed to model-making through his teacher, Julius Plücker, who used models to visualize the properties of special surfaces that arise in line geometry. Afterward, Klein attended Kummer’s seminar in Berlin, where he began to explore the connections between general Kummer surfaces and so-called complex surfaces, first studied by Plücker. In the late 1870s, Klein and Alexander Brill supervised the work of several students at the Munich Technische Hochschule who designed a large collection of models there. There followed a new era in model production, based in Munich but marketed through the Darmstadt firm owned by Brill’s brother. By 1900 the plaster models of L. Brill could be found at leading universities around the world. Our story here centres on Kummer’s famous models, which began as research artefacts in Berlin, before passing to Munich and then proliferating to points beyond.     

A Plücker formula for singular projective varieties

We prove a Plücker formula,for a projective variety X with arbitrary singularities, which expresses the class of X, the degree of the dual variety, in terms of Euler characteristics of X and of two linear sections of X. Moreover, we show that there is no formula whatsoever expressing this degree as a difference of two terms, a deformation invariant and a correction for singularities.     

Some necessary and sufficient conditions satisfied by decomposable tensors in grassmann spaces

The matrix form of the quadratic Plücker relations for decomposable tensors in Grassmann spaces is presented and some equivalent conditions are obtained. The proofs of the equivalence are elementary. The same methods are used to prove an analogous result for subspace incidence.     

Poisson Brackets after Jacobi and Plücker

We construct a symplectic realization and a bi-Hamiltonian formulation of a 3-dimensional system whose solution are the Jacobi elliptic functions. We generalize this system and the related Poisson brackets to higher dimensions. These more general systems are parametrized by lines in projective space. For these rank 2 Poisson brackets the Jacobi identity is satisfied only when the Plücker relations hold. Two of these Poisson brackets are compatible if and only if the corresponding lines in projective space intersect. We present several examples of such systems.     

On the Pontrjagin classes of a submanifold

In this paper the Pontrjagin forms of a closed oriented manifold immersed inR ⁿ are expressed in terms of Plücker coordinates. This work is supported partially by the National Natural Science Foundation of China.     

On reconstruction of a matrix by its minors

In this paper, we reconstruct matrices from their minors, and give explicit formulas for the reconstruction of matrices of orders 2 × 3, 2 × 4, 2 × n, 3 × 6 and m × n. We also formulate the Plücker relations, which are the conditions of the existence of a matrix related to its given minors.     

Differential geometry “in the large” of plane algebraic curves and integral formulas for invariants of singularities

We generalize the Plücker formula for the number of inflection points of a complex projective curve and derive a formula for the number of sextatic points of such a curve. We also obtain an upper estimate for the number of vertices of a real algebraic curve. The proof uses a new result related with integration on the Euler characteristic. Bibliography: 5 titles. Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 231, 1995, pp. 255–268. Translated by N. Yu. Netsvetaev.     

A Primal-Dual Formulation for Certifiable Computations in Schubert Calculus

Formulating a Schubert problem as solutions to a system of equations in either Plücker space or local coordinates of a Schubert cell typically involves more equations than variables. We present a novel primal-dual formulation of any Schubert problem on a Grassmannian or flag manifold as a system of bilinear equations with the same number of equations as variables. This formulation enables numerical computations in the Schubert calculus to be certified using algorithms based on Smale’s \(\alpha \)-theory.     

Decomposable subspaces,linear sections of Grassmann varieties,and higher weights of Grassmann codes

We consider the question of determining the maximum number of points on sections of Grassmannians over finite fields by linear subvarieties of the Plücker projective space of a fixed codimension. This corresponds to a known open problem of determining the complete weight hierarchy of linear error correcting codes associated to Grassmann varieties. We recover most of the known results as well as prove some new results. A basic tool used is a characterization of decomposable subspaces of exterior powers, that is, subspaces in which every nonzero element is decomposable. Also, we use a generalization of the Griesmer–Wei bound that is proved here for arbitrary linear codes.     

Log canonical thresholds of divisors on Grassmannians

Let L be the Plücker line bundle on the Grassmannian. Given D ∈ |kL|, we show that the log canonical threshold of D is at least . The main ingredients of the proof are Kapranov's result on the derived category of coherent sheaves on the Grassmannian, Nadel's vanishing theorem for multiplier ideal sheaves, and Demailly's vanishing theorem for vector bundles.