A Dynamical Interpretation of K Theory for Graph C Star Algebras

Authors

  • Mengqi Gao College of Arts and Sciences, New York University Shanghai, Shanghai 200122, China

DOI:

https://doi.org/10.62051/27qj2b25

Keywords:

K theory, graph C star algebra, etale groupoid, symbolic dynamics, shift space, Smith normal form, essential skeleton, move equivalence.

Abstract

This paper develops a dynamical interpretation of the K theory of graph C star algebras through a systematic analysis of five canonical graph families, selected to isolate distinct dynamical phenomena: transient flow, periodic recurrence, mixing, and component interaction. For each family, the groups  and  are computed and the resulting invariants are correlated with explicit features of the associated graph groupoid and shift dynamics. The free part of  is shown to count irreducible sink components, torsion in  records the period of cyclic subsystems, and the rank of  measures the number of independent cycles in the essential skeleton of the graph. A conjectural dictionary is proposed, linking these algebraic invariants to structural and dynamical properties of directed graphs, and pathways toward rigorous proofs via move equivalence and groupoid homology are indicated. Connections to network robustness, Markov chains, and higher rank graphs are briefly explored.

Downloads

Download data is not yet available.

References

[1] I. Raeburn, Graph Algebras, CBMS Regional Conference Series in Mathematics, vol. 103, American Mathematical Society, Providence, RI, 2005.

[2] A. Kumjian, D. Pask, I. Raeburn, and J. Renault, Graphs, groupoids, and Cuntz Krieger algebras, Journal of Functional Analysis, vol. 144, no. 2, pp. 505 to 541, 1997.

[3] J. Renault, A Groupoid Approach to C Star Algebras, Lecture Notes in Mathematics, vol. 793, Springer, Berlin, 1980.

[4] H. Matui, Etale groupoids arising from products of shifts of finite type, Advances in Mathematics, vol. 303, pp. 502 to 548, 2016.

[5] J. Cuntz and W. Krieger, A class of C star algebras and topological Markov chains, Inventiones Mathematicae, vol. 56, no. 3, pp. 251 to 268, 1980.

[6] D. Lind and B. Marcus, An Introduction to Symbolic Dynamics and Coding, Cambridge University Press, Cambridge, 1995.

[7] A. Tikuisis, S. White, and W. Winter, Quasidiagonality of nuclear C star algebras, Annals of Mathematics, vol. 185, no. 1, pp. 229 to 284, 2017.

[8] A. P. W. Sorensen, Geometric classification of simple graph algebras, Ergodic Theory and Dynamical Systems, vol. 33, no. 4, pp. 1199 to 1220, 2013.

[9] S. Eilers, G. Restorff, E. Ruiz, and A. P. W. Sorensen, Geometric classification of graph C star algebras over finite graphs, Canadian Journal of Mathematics, vol. 70, no. 2, pp. 294 to 353, 2018.

[10] A. Kumjian and D. Pask, Higher rank graph C star algebras, New York Journal of Mathematics, vol. 6, pp. 1 to 20, 2000.

[11] C. Godsil and G. Royle, Algebraic Graph Theory, Graduate Texts in Mathematics, vol. 207, Springer, New York, 2001.

[12] J. R. Norris, Markov Chains, Cambridge Series in Statistical and Probabilistic Mathematics, Cambridge University Press, Cambridge, 1998.

Downloads

Published

13-08-2026

How to Cite

Gao, M. (2026). A Dynamical Interpretation of K Theory for Graph C Star Algebras. Transactions on Computer Science and Intelligent Systems Research, 13, 226-234. https://doi.org/10.62051/27qj2b25