Almost all derivative quivers of artinian biserial rings contain chains

A lower estimate for the number Mn of all labelled
 quivers with n–vertex parts of Artinian biserial rings is given and
 the asymptotic of the relation Mn/Bn, where Bn denotes the number of those quivers all connected components of which are cycles,
 is studied.

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Published in:Algebra and Discrete Mathematics
Date:2003
Main Authors: Avdeeva, T., Ganyushkin, O.
Format: Article
Language:English
Published: Інститут прикладної математики і механіки НАН України 2003
Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/155281
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Cite this:Almost all derivative quivers of artinian biserial rings contain chains / T. Avdeeva, O. Ganyushkin // Algebra and Discrete Mathematics. — 2003. — Vol. 2, № 1. — С. 1–5. — Бібліогр.: 9 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
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author Avdeeva, T.
Ganyushkin, O.
author_facet Avdeeva, T.
Ganyushkin, O.
citation_txt Almost all derivative quivers of artinian biserial rings contain chains / T. Avdeeva, O. Ganyushkin // Algebra and Discrete Mathematics. — 2003. — Vol. 2, № 1. — С. 1–5. — Бібліогр.: 9 назв. — англ.
collection DSpace DC
container_title Algebra and Discrete Mathematics
description A lower estimate for the number Mn of all labelled
 quivers with n–vertex parts of Artinian biserial rings is given and
 the asymptotic of the relation Mn/Bn, where Bn denotes the number of those quivers all connected components of which are cycles,
 is studied.
first_indexed 2025-12-07T18:13:13Z
format Article
fulltext Jo ur na l A lg eb ra D is cr et e M at h.Algebra and Discrete Mathematics RESEARCH ARTICLE Number 2. (2003). pp. 1–5 c© Journal “Algebra and Discrete Mathematics” Almost all derivative quivers of artinian biserial rings contain chains Tetjana Avdeeva and Olexandr Ganyushkin Communicated by V. V. Kirichenko Abstract. A lower estimate for the number Mn of all labelled quivers with n–vertex parts of Artinian biserial rings is given and the asymptotic of the relation Mn/Bn, where Bn denotes the num- ber of those quivers all connected components of which are cycles, is studied. In the beginning of 70-s P.Gabriel [1] introduced a notion of a quiver of a finite dimensional algebra over an algebraically closed field — an directed graph of special type which in concise form preserves some very important information about the algebra. Using these graphs in [1] (see also Krugliak [2]) all finite dimensional algebras of finite type over an algebraically closed field with square zero radical are described. Later V.Kirichenko has expanded the construction of such an directed graph to right Noetherian semiperfect rings [3], and then to several other classes of rings (see, for example, [4], [5] and bibliography there). For some classes of rings it is convenient to consider a so called derivative quiver RQ(A) (see [6]), which for the rings under consideration always turns out to be a simple bipartite graph with equicardinal part, instead of a quiver Q(A) of a ring A. In this connection there arises a natural problem of investigation of graphs which can be quivers of rings of some class. We will deal with Artinian biserial rings, first introduced by .Fuller [7]. A starting point for this paper is the following statement( [4], Corollary 5.15): An Artinian ring A, with square zero Jacobson radical is biserial if and only if its derivative quiver RQ(A) is a disconnected union of chains and cycles. 2000 Mathematics Subject Classification: 05C30, 05C38, 16P20. Key words and phrases: artinian rings, quivers, bipartite graphs. Jo ur na l A lg eb ra D is cr et e M at h.2 Almost all derivative quivers.. Therefore, a derivative quiver of an Artinian biserial ring is a simple bipartite graph with parts of the same cardinality, in which the degree of each vertex does not exceed 2. In [8] such graphs have been called Artinian–biserial, or just AB–graphs. An AB–graph with n–vertex parts is called labelled, if the vertices of each part are numbered from 1 to n and it is indicated, which of the parts is lower, and which is upper. In what follows we consider only labelled AB–graphs. In [8] the number Bn of those AB–graphs with n–vertex parts, all connected components of which are cycles, is counted: Bn = ∑ (l1,l2,...,ln) 1l1+2l2+···+nln=n (n!)2 (l1!)2 n ∏ k=2 (2lk · klk · lk!) , (1) and an upper bound for the number Mn of all labelled AB–graphs with n–vertex parts is obtained: Mn < n ∑ k=0 (−1)k ( n k ) n! (n − k)! ∣ ∣ISn−k ∣ ∣ 2 , where ∣ ∣ISn ∣ ∣ — is the order of the inverse symmetric semigroup ISn of degree n. This estimate, however, is rather rough. Beside this, to give an estimate for the order in the right-hand side of the latter inequality for large values of n is itself a difficult problem. A more effective lower estimate for Mn is given in the following Lemma. The number Mn of all labelled AB–graphs with n–vertex parts satisfies the inequality Mn > (n!)2 · n 2 . Proof. Since M1 = 2 and M2 = 16 then the statement is obvious for n = 1 and for n = 2. Let now n ≥ 3 and suppose that for all k < n the statement of Lemma is true. Consider those AB–graphs, which contain a sufficiently long chain of an odd length. Then exactly one of the endpoints of such a chain will belong to the lower part. To determine a chain of length 2n− 2k− 1, one has to choose its endpoint in the lower part, then a vertex in the upper part incident to this endpoint, then the next vertex of a chain in the lower part, and so on, each time switching the part of the next vertex choice, till one reaches the 2n − 2k–s vertex of the chain which is its endpoint from the upper part. Since in this way one will get every chain of length 2n − 2k − 1 exactly one time then the number of different chains of length 2n − 2k − 1 equals n · n · (n − 1) · (n − 1) · (n − 2) · (n − 2) · · · (k + 1) · (k + 1) = (n!)2 (k!)2 . Jo ur na l A lg eb ra D is cr et e M at h.T. Avdeeva, O. Ganyushkin 3 Since for k ≤ n − 1 2 an AB–graph with n–vertex parts can not contain more than one chain of length 2n − 2k − 1 then for such values of k the number of AB–graphs, containing a chain of length 2n − 2k − 1, equals (n!)2 (k!)2 ·Mk. By the inductive assumption Mk > (k!)2 · k 2 . Using the equality M1 = 2, we can assume Mk > (k!)2. It is easily seen, that an AB–graph with n–vertex parts can contain only one chain of length ≥ n. Therefore, Mn > [(n−1)/2] ∑ k=0 ( n! k! )2 (k!)2 = (n!)2 · [(n−1)/2] ∑ k=0 1 = (n!)2 · [ n − 1 2 ] > (n!)2 · n 2 . Theorem. Let Mn be the number of all labelled AB–graphs with n– vertex parts, and Bn — the number of those of such graphs, all connected components of which are cycles. Then lim n→∞ Bn Mn = 0. Proof. Let us calculate an upper bound for Bn. It is known, that the number of permutations of a cycle type (l1, l2, . . . , ln) equals n! · ( ∏n k=1(k lk · lk!) ) −1 . Since the number of all permutations is n!, then ∑ (l1,l2,...,ln) 1l1+2l2+···+nln=n n! n ∏ k=1 (klk · lk!) = n!. After cancellation of both sides by n! we obtain: ∑ (l1,l2,...,ln) 1l1+2l2+···+nln=n 1 n ∏ k=1 (klk · lk!) = 1. This equality and an obvious inequality l1! · ∏n k=2 2lk ≥ 1, imply: ∑ (l1,l2,...,ln) 1l1+2l2+···+nln=n 1 (l1!)2 n ∏ k=2 (2lk · klk · lk!) = = ∑ (l1,l2,...,ln) 1l1+2l2+···+nln=n 1 n ∏ k=1 (klk · lk!) · 1 l1! n ∏ k=2 2lk < < ∑ (l1,l2,...,ln) 1l1+2l2+···+nln=n 1 n ∏ k=1 (klk · lk!) = 1. Jo ur na l A lg eb ra D is cr et e M at h.4 Almost all derivative quivers.. This inequality and inequality 1 now imply, that Bn < (n!)2. Therefore, using Lemma, we obtain: 0 ≤ Bn Mn ≤ (n!)2 (n!)2 · n 2 = 2 n . Thus, lim n→∞ Bn Mn = 0. Following the tradition for usage of the expression ‘almost all’ (see, for example, [9]), we obtain the following Corollary. Almost all AB–graphs with n–vertex parts contain chains. We conclude by stating the values of Bn and Mn and of the relation Bn/Mn for small values of n: n 2 3 4 5 Bn 2 16 151 4991 Mn 16 265 7343 304186 Bn/Mn 0.125 0.0603773 0.0205638 0.0164077 References [1] Gabriel P. Unzerlegbare Darstellungen 1. Manuscript Math. 6 (1972), 71–103. [5] [2] Krugliak.S.A. Representations of algebras with zero sguare radical. Zapiski nauchn. seminarov LOMI Ac.Sci. USSR 28 (1972), 80–89. (in Russian) [3] Kirichenko, V.V. Generalized uniserial rings, Math. Sb. (N.S.), 99 (141), N 4, (1976), pp. 559-581. English translation, Math USSR Sb., v. 28, N 4, 1976, pp. 501-520. [4] Danlyev Kh.M., Kirichenko V.V., Haletskaja Z.P., Jaremenko Ju.V. Weakly prime semiperfect 2–rings and modules over them. Algebraicheskie issledovania (collec- tion of papers), Institut mathematiki NAN Ukrainy, Kiev, 1995, 5–32. [5] Gubareni N.M., Kirichenko V.V. Rings and Modules. - Czestochowa, 2001. [6] Kirichenko V.V., Bernik O.Ja. Semiperfect rings of distributive module type. Dopovidi Ac.Sci. URSR. 1988, no. 3, 15–17. [7] Fuller K.R. Weakly symmetric rings of distributive module type. Comm. in Alge- bra. 5 (1977), 997–1008. [8] Avdeeva T.V., Ganyushkin O.G. The number of quivers of Artinian biserial rings. Visnyk Kyivs’kogo Univ., ser. phiz.–math. sci., 1999, no. 3, 18–27. (in Ukrainian) [9] Korshunov A.D. Main properties of random graphs with large number of vertices and edges. Uspehi mathem.nauk 40 (1985), 1(241), 107–173.(in Russian) Jo ur na l A lg eb ra D is cr et e M at h.T. Avdeeva, O. Ganyushkin 5 Contact information T. Avdeeva Department of Physics and Mathematics, National of Technical University of Ukraine ”Kyiv of Polytechnical Institute”,37, Peremohy pr., Kyiv,UKRAINE O. Ganyushkin Department of Mechanics and Mathematics, Kyiv Taras Shevchenko University, 64, Volodymyrska st., 01033, Kyiv, UKRAINE E-Mail: ganiyshk@mechmat.univ.kiev.ua Received by the editors: 06.12.2002.
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institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
issn 1726-3255
language English
last_indexed 2025-12-07T18:13:13Z
publishDate 2003
publisher Інститут прикладної математики і механіки НАН України
record_format dspace
spelling Avdeeva, T.
Ganyushkin, O.
2019-06-16T15:30:56Z
2019-06-16T15:30:56Z
2003
Almost all derivative quivers of artinian biserial rings contain chains / T. Avdeeva, O. Ganyushkin // Algebra and Discrete Mathematics. — 2003. — Vol. 2, № 1. — С. 1–5. — Бібліогр.: 9 назв. — англ.
1726-3255
2000 Mathematics Subject Classification: 05C30, 05C38, 16P20.
https://nasplib.isofts.kiev.ua/handle/123456789/155281
A lower estimate for the number Mn of all labelled&#xd; quivers with n–vertex parts of Artinian biserial rings is given and&#xd; the asymptotic of the relation Mn/Bn, where Bn denotes the number of those quivers all connected components of which are cycles,&#xd; is studied.
en
Інститут прикладної математики і механіки НАН України
Algebra and Discrete Mathematics
Almost all derivative quivers of artinian biserial rings contain chains
Article
published earlier
spellingShingle Almost all derivative quivers of artinian biserial rings contain chains
Avdeeva, T.
Ganyushkin, O.
title Almost all derivative quivers of artinian biserial rings contain chains
title_full Almost all derivative quivers of artinian biserial rings contain chains
title_fullStr Almost all derivative quivers of artinian biserial rings contain chains
title_full_unstemmed Almost all derivative quivers of artinian biserial rings contain chains
title_short Almost all derivative quivers of artinian biserial rings contain chains
title_sort almost all derivative quivers of artinian biserial rings contain chains
url https://nasplib.isofts.kiev.ua/handle/123456789/155281
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AT ganyushkino almostallderivativequiversofartinianbiserialringscontainchains