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Related papers: Testing isomorphism between tuples of subspaces

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In this paper, we propose algorithms for the graph isomorphism (GI) problem that are based on the eigendecompositions of the adjacency matrices. The eigenvalues of isomorphic graphs are identical. However, two graphs $ G_A $ and $ G_B $ can…

Discrete Mathematics · Computer Science 2019-08-14 Stefan Klus , Tuhin Sahai

Color refinement is a classical technique used to show that two given graphs G and H are non-isomorphic; it is very efficient, although it does not succeed on all graphs. We call a graph G amenable to color refinement if it succeeds in…

Computational Complexity · Computer Science 2015-05-05 V. Arvind , Johannes Köbler , Gaurav Rattan , Oleg Verbitsky

It's important to design polynomial time algorithms to test if two graphs are isomorphic at least for some special classes of graphs. An approach to this was presented by Eugene M. Luks(1981) in the work \textit{Isomorphism of Graphs of…

Discrete Mathematics · Computer Science 2012-09-06 Adria Alcala Mena

We construct a new category of vector spaces which contains both the standard category of vector spaces and Grassmannians. Its space of objects classifies vector bundles, its space of morphisms classifies bundle isomorphisms, and it can be…

Algebraic Topology · Mathematics 2017-11-09 Yi-Sheng Wang

An $n$-tuple of operators $(V_1,...,V_n)$ acting on a Hilbert space $H$ is said to be isometric if the operator $[V_1\...\ V_n]:H^n\to H$ is an isometry. We prove a decomposition for an isometric tuple of operators that generalizes the…

Operator Algebras · Mathematics 2015-09-15 Matthew Kennedy

The set of matrix tuples with invariant subspaces whose dimensions sum up to the dimension of the space, but which do not span the whole space form an algebraic hypersurface. We found the equation of this hypersurface. This generalizes…

Algebraic Geometry · Mathematics 2026-04-27 Tamás Bencze

In this paper, we address the following two general problems: given two algebraic varieties in ${\bf C}^n$, find out whether or not they are (1) isomorphic; (2) equivalent under an automorphism of ${\bf C}^n$. Although a complete solution…

Algebraic Geometry · Mathematics 2016-09-07 Vladimir Shpilrain , Jie-Tai Yu

This article deals with new polynomial time algorithm for graph isomorphism testing.

Data Structures and Algorithms · Computer Science 2013-06-19 Michael I. Trofimov

We prove that there is a graph isomorphism test running in time $n^{\operatorname{polylog}(h)}$ on $n$-vertex graphs excluding some $h$-vertex graph as a minor. Previously known bounds were $n^{\operatorname{poly}(h)}$ (Ponomarenko, 1988)…

Data Structures and Algorithms · Computer Science 2023-05-30 Martin Grohe , Daniel Neuen , Daniel Wiebking

Graph isomorphism is an important computer science problem. The problem for the general case is unknown to be in polynomial time. The base algorithm for the general case works in quasi-polynomial time. The solutions in polynomial time for…

Discrete Mathematics · Computer Science 2017-11-23 Vaibhav Amit Patel

Correspondence homomorphisms are both a generalization of standard homomorphisms and a generalization of correspondence colourings. For a fixed target graph $H$, the problem is to decide whether an input graph $G$, with each edge labeled by…

Discrete Mathematics · Computer Science 2018-03-30 Tomas Feder , Pavol Hell

A classical difficult isomorphism testing problem is to test isomorphism of p-groups of class 2 and exponent p in time polynomial in the group order. It is known that this problem can be reduced to solving the alternating matrix space…

Data Structures and Algorithms · Computer Science 2017-10-03 Yinan Li , Youming Qiao

This paper investigates type isomorphism in a lambda-calculus with intersection and union types. It is known that in lambda-calculus, the isomorphism between two types is realised by a pair of terms inverse one each other. Notably,…

Logic in Computer Science · Computer Science 2015-08-12 Mario Coppo , Mariangiola Dezani-Ciancaglini , Ines Margaria , Maddalena Zacchi

The Weisfeiler-Leman procedure is a widely-used technique for graph isomorphism testing that works by iteratively computing an isomorphism-invariant coloring of vertex tuples. Meanwhile, a fundamental tool in structural graph theory, which…

Discrete Mathematics · Computer Science 2022-07-19 Sandra Kiefer , Daniel Neuen

We prove two isomorphism-invariance theorems for groupoids associated with ultragraphs. These theorems characterize ultragraphs for which the topological full group of an associated groupoid is an isomorphism invariant. These results extend…

Dynamical Systems · Mathematics 2020-05-06 Gilles Gonçalves de Castro , Daniel Gonçalves , Daniel W van Wyk

This paper presents a new graph isomorphism invariant, called $\mathfrak{w}$-labeling, that can be used to design a polynomial-time algorithm for solving the graph isomorphism problem for various graph classes. For example, all…

Data Structures and Algorithms · Computer Science 2023-01-24 Alpár Jüttner , Péter Madarasi

Graph isomorphism is an important problem as its worst-case time complexity is not yet fully understood. In this study, we try to draw parallels between a related optimization problem called point set registration. A graph can be…

Optimization and Control · Mathematics 2021-11-19 Yigit Oktar

Given locally compact quantum groups $\G_1$ and $\G_2$, we show that if the convolution algebras $L^1(\G_1)$ and $L^1(\G_2)$ are isometrically isomorphic as algebras, then $\G_1$ is isomorphic either to $\G_2$ or the commutant $\G_2'$.…

Operator Algebras · Mathematics 2012-02-17 Matthew Daws , Hung Le Pham

In this article, we study the isomorphism problem for the algebras of $\Phi-$Pseudofunctions and $\Phi-$Pseudomeasures, denoted by $PF_\Phi(G)$ and $PM_\Phi(G),$ respectively. More precisely, for a certain class of Young functions $\Phi,$…

Functional Analysis · Mathematics 2025-07-18 Arvish Dabra , N. Shravan Kumar

We give an isomorphism test for graphs of Euler genus $g$ running in time $2^{O(g^4 \log g)}n^{O(1)}$. Our algorithm provides the first explicit upper bound on the dependence on $g$ for an fpt isomorphism test parameterized by the Euler…

Data Structures and Algorithms · Computer Science 2024-03-08 Daniel Neuen
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