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Related papers: Degenerate flag varieties in network coding

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The application of flags to network coding has been introduced recently by Liebhold, Nebe, and Vazquez-Castro. It is a variant to random linear network coding and explicit routing solutions for given networks. Here we study lower and upper…

Combinatorics · Mathematics 2021-10-12 Sascha Kurz

In this paper we extend the study of linear spaces of upper triangular matrices endowed with the flag-rank metric. Such metric spaces are isometric to certain spaces of degenerate flags and have been suggested as suitable framework for…

Combinatorics · Mathematics 2023-03-30 Gianira N. Alfarano , Alessandro Neri , Ferdinando Zullo

The multiplicative-additive finite-field matrix channel arises as an adequate model for linear network coding systems when links are subject to errors and erasures, and both the network topology and the network code are unknown. In a…

Information Theory · Computer Science 2010-04-13 Roberto W. Nobrega , Bartolomeu F. Uchoa-Filho

We develop a network coding technique based on flags of subspaces and a corresponding network channel model. To define error correcting codes we introduce a new distance on the flag variety, the Grassmann distance on flags and compare it to…

Information Theory · Computer Science 2016-12-22 Dirk Liebhold , Gabriele Nebe , Angeles Vazquez-Castro

Motivated by bases of representations compatible with the PBW filtration for basic Lie superalgebras by Kus and Fourier, we generalise the construction of degenerations of flag varieties via favourable modules to the super setup. In the…

Algebraic Geometry · Mathematics 2026-05-07 Ibrahim Ahmad

We study linear degenerations of flag varieties from the point of view of tropical geometry. We define the linear degenerate flag Dressian and prove a correspondence between: $(a)$ points in the linear degenerate flag Dressian, $(b)$ linear…

Combinatorics · Mathematics 2023-08-09 Alessio Borzì , Victoria Schleis

Linear degenerate flag varieties are degenerations of flag varieties as quiver Grassmannians. For type A flag varieties, we obtain characterizations of flatness, irreducibility and normality of these degenerations via rank tuples. Some of…

Algebraic Geometry · Mathematics 2018-04-11 Giovanni Cerulli Irelli , Xin Fang , Evgeny Feigin , Ghislain Fourier , Markus Reineke

In network coding, a flag code is a collection of flags, that is, sequences of nested subspaces of a vector space over a finite field. Due to its definition as the sum of the corresponding subspace distances, the flag distance parameter…

Information Theory · Computer Science 2021-12-01 Clementa Alonso-González , Miguel Ángel Navarro-Pérez

We propose a new class of space-time block codes based on finite-field rank-metric codes in combination with a rank-metric-preserving mapping to the set of Eisenstein integers. It is shown that these codes achieve maximum diversity order…

Information Theory · Computer Science 2017-05-30 Sven Puchinger , Sebastian Stern , Martin Bossert , Robert F. H. Fischer

Alignment, the tendency of adjacent weight matrices in deep networks to develop compatible subspace orientations, underlies gradient flow, Neural Collapse, and representation similarity across architectures. Despite extensive empirical…

Machine Learning · Computer Science 2026-05-12 Jingchuan Xiao , Xinyi Sui , Cihan Ruan

Flag manifolds encode nested sequences of subspaces and serve as powerful structures for various computer vision and machine learning applications. Despite their utility in tasks such as dimensionality reduction, motion averaging, and…

Computer Vision and Pattern Recognition · Computer Science 2025-06-05 Nathan Mankovich , Ignacio Santamaria , Gustau Camps-Valls , Tolga Birdal

We show that in type A or C any degenerate flag variety is in fact isomorphic to a Schubert variety in an appropriate partial flag manifold.

Representation Theory · Mathematics 2014-07-17 Giovanni Cerulli Irelli , Martina Lanini

Random network coding recently attracts attention as a technique to disseminate information in a network. This paper considers a non-coherent multi-shot network, where the unknown and time-variant network is used several times. In order to…

Information Theory · Computer Science 2016-11-17 Antonia Wachter-Zeh , Markus Stinner , Vladimir Sidorenko

Error control is significant to network coding, since when unchecked, errors greatly deteriorate the throughput gains of network coding and seriously undermine both reliability and security of data. Two families of codes, subspace and rank…

Information Theory · Computer Science 2012-05-04 Zhiyuan Yan , Hongmei Xie

The shape and orientation of data clouds reflect variability in observations that can confound pattern recognition systems. Subspace methods, utilizing Grassmann manifolds, have been a great aid in dealing with such variability. However,…

Computer Vision and Pattern Recognition · Computer Science 2020-06-26 Xiaofeng Ma , Michael Kirby , Chris Peterson

In this work we will present algorithms for decoding rank metric codes. First we will look at a new decoding algorithm for Gabidulin codes using the property of Dickson matrices corresponding to linearized polynomials. We will be using a…

Information Theory · Computer Science 2018-02-01 Tovohery Hajatiana Randrianarisoa

Subspace codes were introduced by K\"otter and Kschischang for error control in random linear network coding. In this paper, a layered type of subspace codes is considered, which can be viewed as a superposition of multiple component…

Information Theory · Computer Science 2012-09-14 Chao Chen , Hongmei Xie , Baoming Bai

We continue, generalize and expand our study of linear degenerations of flag varieties from [G. Cerulli Irelli, X. Fang, E. Feigin, G. Fourier, M. Reineke, Math. Z. 287 (2017), no. 1-2, 615-654]. We realize partial flag varieties as quiver…

Algebraic Geometry · Mathematics 2019-02-01 Giovanni Cerulli Irelli , Xin Fang , Evgeny Feigin , Ghislain Fourier , Markus Reineke

We study finite dimensional approximations to degenerate versions of affine flag varieties using quiver Grassmannians for cyclic quivers. We prove that they admit cellular decompositions parametrized by affine Dellac configurations, and…

Algebraic Geometry · Mathematics 2024-11-08 Alexander Pütz

The goal of this paper is to study the link between the topology of the degenerate flag varieties and combinatorics of the Dellac configurations. We define three new classes of algebraic varieties closely related to the degenerate flag…

Combinatorics · Mathematics 2018-08-14 Ange Bigeni , Evgeny Feigin
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