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On the jacobian group of a cone over a circulant graph. / Grunwald, L. A.; Mednykh, I. A.
In: Mathematical Notes of NEFU, Vol. 28, No. 2, 6, 03.2021, p. 88-101.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - On the jacobian group of a cone over a circulant graph
AU - Grunwald, L. A.
AU - Mednykh, I. A.
N1 - Funding Information: The study of the second named author was carried out within the framework of the state contract of the Sobolev Institute of Mathematics (project no. 0314-2019-0007). Publisher Copyright: © 2021 L. A. Grunwald and I. A. Mednykh.
PY - 2021/3
Y1 - 2021/3
N2 - For any given graph G, consider the graph Ĝ which is a cone over G. We study two important invariants of such a cone, namely, the complexity (the number of spanning trees) and the Jacobian of the graph. We prove that complexity of graph Ĝ coincides with the number of rooted spanning forests in G and the Jacobian of Ĝ is isomorphic to the cokernel of the operator I + L(G), where L(G) is the Laplacian of G and I is the identity matrix. As a consequence, one can calculate the complexity of Ĝ as det(I + L(G)). As an application, we establish general structural theorems for the Jacobian of Ĝ in the case when G is a circulant graph or cobordism of two circulant graphs.
AB - For any given graph G, consider the graph Ĝ which is a cone over G. We study two important invariants of such a cone, namely, the complexity (the number of spanning trees) and the Jacobian of the graph. We prove that complexity of graph Ĝ coincides with the number of rooted spanning forests in G and the Jacobian of Ĝ is isomorphic to the cokernel of the operator I + L(G), where L(G) is the Laplacian of G and I is the identity matrix. As a consequence, one can calculate the complexity of Ĝ as det(I + L(G)). As an application, we establish general structural theorems for the Jacobian of Ĝ in the case when G is a circulant graph or cobordism of two circulant graphs.
KW - Chebyshev polynomial
KW - Circulant graph
KW - Cone over graph
KW - Laplacian matrix
KW - Spanning forest
KW - Spanning tree
UR - http://www.scopus.com/inward/record.url?scp=85112403009&partnerID=8YFLogxK
UR - https://elibrary.ru/item.asp?id=46343993
U2 - 10.25587/SVFU.2021.32.84.006
DO - 10.25587/SVFU.2021.32.84.006
M3 - Article
AN - SCOPUS:85112403009
VL - 28
SP - 88
EP - 101
JO - Математические заметки СВФУ
JF - Математические заметки СВФУ
SN - 2411-9326
IS - 2
M1 - 6
ER -
ID: 34097112