Initial degenerations of Grassmannians

نویسندگان

چکیده

We construct closed immersions from initial degenerations of $${{\,\mathrm{Gr}\,}}_{0}(d,n)$$ —the open cell in the Grassmannian $${{\,\mathrm{Gr}\,}}(d,n)$$ given by nonvanishing all Plücker coordinates—to limits thin Schubert cells associated to diagrams induced face poset corresponding tropical linear space. These are isomorphisms when (d, n) equals (2, n), (3, 6) and 7). As an application we prove $${{\,\mathrm{Gr}\,}}_0(3,7)$$ is schön, Chow quotient $${{\,\mathrm{Gr}\,}}(3,7)$$ maximal torus $$ {\text {PGL}}(7)$$ log canonical compactification moduli space 7 points $${\mathbb {P}}^2$$ general position, making progress on a conjecture Hacking, Keel, Tevelev.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Degenerations of Surface Scrolls and the Gromov-Witten Invariants of Grassmannians

We describe an algorithm for computing certain characteristic numbers of rational normal surface scrolls using degenerations. As a corollary we obtain an efficient method for computing the corresponding Gromov-Witten invariants of the Grassmannians of lines.

متن کامل

Corneal Degenerations

Degenerations are defi ned as the gradual deterioration of a tissue or an organ that was previously normal with frequent loss of functional activity. Corneal degenerations are characterized by the deposition of material, thinning of tissue, and vascularization. Contrary to corneal dystrophies, they are not hereditary and could be unilateral. Moreover, because of the continuous exposure to envir...

متن کامل

Degenerations of Abelian Differentials

Consider degenerations of Abelian differentials with prescribed number and multiplicity of zeros and poles. Motivated by the theory of limit linear series, we define twisted canonical divisors on pointed nodal curves to study degenerate differentials, give dimension bounds for their moduli spaces, and establish smoothability criteria. As applications, we show that the spin parity of holomorphic...

متن کامل

Incompressibility of Orthogonal Grassmannians

We prove the following conjecture due to Bryant Mathews (2008). Let Q be the orthogonal grassmannian of totally isotropic i-planes of a non-degenerate quadratic form q over an arbitrary field (where i is an integer satisfying 1 ≤ i ≤ (dim q)/2). If the degree of each closed point on Q is divisible by 2 and the Witt index of q over the function field of Q is equal to i, then the variety Q is 2-i...

متن کامل

Embeddings of Orthogonal Grassmannians

In this paper I survey a few recent results on projective and Veronesean embeddings of orthogonal Grassmannian and propose a few conjectures

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Selecta Mathematica-new Series

سال: 2021

ISSN: ['1022-1824', '1420-9020']

DOI: https://doi.org/10.1007/s00029-021-00679-6