Matching Tag: real-schubert-calculus
Let V ∈ Gr k , n ( R ) V\in\operatorname{Gr}_{k,n}(\mathbb{R}) V ∈ Gr k , n ( R ) . Suppose that all complex zeros of the Wronskian Wr ( V ) \operatorname{Wr}(V) Wr ( V ) are real, and let I ⊆ R I\subseteq\mathbb{R} I ⊆ R be any interval on wh…
Let α = { α 1 < ⋯ < α k } \alpha=\{\alpha_1<\dotsb<\alpha_k\} α = { α 1 < ⋯ < α k } with α k < n \alpha_k<n α k < n , and let ( w 1 , … , w m ) (w_1,\dotsc,w_m) ( w 1 , … , w m ) be a Schubert problem for F ℓ ( α ; n ) \mathbb{F}\ell(\alpha;n) F ℓ ( α ; n ) . For each permutation w i w_i w i , let…
Let m , p > 1 m,p>1 m , p > 1 , let Grass ( p , m + p ) \operatorname{Grass}(p,m+p) Grass ( p , m + p ) be the Grassmannian, and let α 1 , … , α n \alpha^1,\ldots,\alpha^n α 1 , … , α n be Schubert data. A real upper-triangular matrix with diagonal entries 1 1 1 is…
Let γ \gamma γ be the rational normal curve, and for a set S i = { s i 1 , … , s i n } S_i=\{s_{i1},\dotsc,s_{in}\} S i = { s i 1 , … , s in } of n n n distinct points of R P 1 \mathbb{R}\mathbb{P}^1 R P 1 , let F ∙ ( S i ) F_\bullet(S_i) F ∙ ( S i ) be the flag whose…
Let ( w 1 , … , w m ) (w_1,\dotsc,w_m) ( w 1 , … , w m ) be a Grassmannian Schubert problem for F ℓ ( α ; n ) \mathbb{F}\ell(\alpha;n) F ℓ ( α ; n ) , let δ ( w i ) \delta(w_i) δ ( w i ) be the unique descent of w i w_i w i , and let Δ w ( t 1 , … , t m ) \Delta_w(t_1,\dotsc,t_m) Δ w ( t 1 , … , t m ) be it…
Let α = { α 1 < ⋯ < α k } \alpha=\{\alpha_1<\dotsb<\alpha_k\} α = { α 1 < ⋯ < α k } with α k < n \alpha_k<n α k < n , and let ( w 1 , … , w m ) (w_1,\dotsc,w_m) ( w 1 , … , w m ) be a Grassmannian Schubert problem for F ℓ ( α ; n ) \mathbb{F}\ell(\alpha;n) F ℓ ( α ; n ) . Let…
Let a = ( a 1 < ⋯ < a k ) a=(a_1<\dotsb<a_k) a = ( a 1 < ⋯ < a k ) and n n n be positive integers with a k < n a_k<n a k < n . Let W a W^a W a index Schubert varieties on F ℓ ( a ; n ) \mathbb F\ell(a;n) F ℓ ( a ; n ) , and let w 1 , … , w m ∈ W a w_1,\dotsc,w_m\in W^a w 1 , … , w m ∈ W a be data for a Schube…
Let γ : R → R m − 1 [ u ] \gamma:\mathbb{R}\to\mathbb{R}_{m-1}[u] γ : R → R m − 1 [ u ] be a convex curve, meaning that any m m m distinct points along γ \gamma γ are linearly independent. Let z 1 , … , z d ( m − d ) z_1,\dots,z_{d(m-d)} z 1 , … , z d ( m − d ) be distinc…
Let ν ⊢ n \nu\vdash n ν ⊢ n and let μ ⊩ κ \boldsymbol{\mu}\Vdash\kappa μ ⊩ κ , where κ = ( κ 1 , … , κ s ) \kappa=(\kappa_1,\dots,\kappa_s) κ = ( κ 1 , … , κ s ) is a composition of n n n . Let I 1 , … , I s ⊆ R I_1,\dots,I_s\subseteq\mathbb{R} I 1 , … , I s ⊆ R be pairwise disjo…
Let 0 ≤ k ≤ n 0\le k\le n 0 ≤ k ≤ n , and let I 1 , … , I k ( n − k ) I_1,\dots,I_{k(n-k)} I 1 , … , I k ( n − k ) be pairwise disjoint intervals of P 1 ( R ) \mathbb{P}^1(\mathbb{R}) P 1 ( R ) . For each l l l , let X l X_l X l be a multiset of k k k points in I l I_l I l , and le…
Consider a real Schubert problem for which Proposition … is sharp. The conjecture asserts that the cohomological lower bound can always be attained; the supplied excerpt gives no r…
Monotone Osculating Conjecture. For any such Schubert problem and any flags F ∙ 1 , … , F ∙ m F_{\bullet}^1,\ldots,F_{\bullet}^m F ∙ 1 , … , F ∙ m osculating γ \gamma γ at points that are monotone with respect to the…
Monotone Secant Conjecture. For any Grassmannian Schubert problem ( σ 1 , … , σ m ) (\sigma_1,\ldots, \sigma_m) ( σ 1 , … , σ m ) on F ℓ ( α ; n ) \mathbb{F}\ell(\alpha;n) F ℓ ( α ; n ) and any disjoint secant flags…
Let G ( k , n ) G(k,n) G ( k , n ) be a Grassmannian, let γ \gamma γ be a rational normal curve, and let λ 1 , … , λ m \lambda^1,\dotsc,\lambda^m λ 1 , … , λ m be a Schubert problem on G ( k , n ) G(k,n) G ( k , n ) . A generalized secant subspace to…