Results 1 to 10 of about 3,252 (223)
Non-planar BCFW Grassmannian geometries
Journal of High Energy Physics, 2022 In this paper, we study non-adjacent BCFW recursion relations and their connection to positive geometry. For an adjacent BCFW shift, the n-point N k MHV tree-level amplitude in N $$ \mathcal{N} $$ = 4 SYM theory is expressed as a sum over planar on-shell
Shruti Paranjape +2 more
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Network parameterizations for the Grassmannian [PDF]
Discrete Mathematics & Theoretical Computer Science, 2013 Deodhar introduced his decomposition of partial flag varieties as a tool for understanding Kazhdan-Lusztig polynomials. The Deodhar decomposition of the Grassmannian is also useful in the context of soliton solutions to the KP equation, as shown by ...
Kelli Talaska, Lauren Williams
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Spread Spectrum Modulation with Grassmannian Constellations for Mobile Multiple Access Underwater Acoustic Channels [PDF]
Sensors, 2022 The objective of this study is to evaluate Grassmannian constellations combined with a spread spectrum multiple access scheme for underwater acoustic mobile multiple access communication systems.
Christophe Bernard +2 more
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A Family Of Low Density Matrices In Lagrangian–Grassmannian
Special Matrices, 2018 The aim of this paper is twofold. First, we show a connection between the Lagrangian- Grassmannian variety geometry defined over a finite field with q elements and the q-ary Low-Density Parity- Check codes. Second, considering the Lagrangian-Grassmannian
Carrillo-Pacheco Jesús +1 more
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Combinatorics of diagrams of permutations [PDF]
Discrete Mathematics & Theoretical Computer Science, 2014 There are numerous combinatorial objects associated to a Grassmannian permutation $w_λ$ that index cells of the totally nonnegative Grassmannian. We study some of these objects (rook placements, acyclic orientations, various restricted fillings) and ...
Joel Brewster Lewis, Alejandro Morales
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Total positivity for the Lagrangian Grassmannian [PDF]
Discrete Mathematics & Theoretical Computer Science, 2020 The positroid decomposition of the Grassmannian refines the well-known Schubert decomposition, and has a rich combinatorial structure. There are a number of interesting combinatorial posets which index positroid varieties,just as Young diagrams index ...
Rachel Karpman
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A Combinatorial Approach to Multiplicity-Free Richardson Subvarieties of the Grassmannian [PDF]
Discrete Mathematics & Theoretical Computer Science, 2009 We consider Buch's rule for K-theory of the Grassmannian, in the Schur multiplicity-free cases classified by Stembridge. Using a result of Knutson, one sees that Buch's coefficients are related to Möbius inversion. We give a direct combinatorial proof of
Michelle Snider
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K-classes for matroids and equivariant localization [PDF]
Discrete Mathematics & Theoretical Computer Science, 2011 To every matroid, we associate a class in the K-theory of the Grassmannian. We study this class using the method of equivariant localization. In particular, we provide a geometric interpretation of the Tutte polynomial.
Alex Fink, David Speyer
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Integral geometry on discrete matrices
Moroccan Journal of Pure and Applied Analysis, 2021 In this note, we study the Radon transform and its dual on the discrete matrices by defining hyperplanes as being infinite sets of solutions of linear Diophantine equations. We then give an inversion formula and a support theorem.
Attioui Abdelbaki
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Affine type A geometric crystal structure on the Grassmannian [PDF]
Discrete Mathematics & Theoretical Computer Science, 2020 We construct a type A(1) n−1 affine geometric crystal structure on the Grassmannian Gr(k, n). The tropicalization of this structure recovers the combinatorics of crystal operators on semistandard Young tableaux of rectangular shape (with n − k rows ...
Gabriel Frieden
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