The set of eigenvalues of a matrix associated with a tree is called the spectrum of the tree. In this talk, we present how the presence of certain subtrees in a tree T "forces" specific real numbers to be in the adjacency, Laplacian and distance spectra of the tree T. These real numbers  (eigenvalues) are not necessarily in the spectrum of the subtrees. In fact, every possible eigenvalue of the adjacency matrix of a tree can be forced in this way. This has important implications for the spectra of random trees.

Speaker: Dr Kenneth Dadedzi | Department of Mathematics  |  University of Ghana

Chairperson: Dr Eyram Schwinger | Department of Mathematics | University of Ghana 

Meeting ID: 319 123 982 353 | Passcode: LWX4bf | Teams: Link 

All are cordially invited.

Bio

Dr. Dadedzi is currently a lecturer in the Department of Mathematics at the University of Ghana. He earned both his master’s and doctorate degrees from Stellenbosch University in South Africa. He is also an AIMS - South Africa Alumni. Previously, he worked as a teaching assistant at the University of Cape Coast (UCC), Ghana. Dr. Dadedzi’s research focuses on Spectral Graph Theory, which involves the study of eigenvalues of matrices associated with graphs. He also has an interest in enumerative and analytic combinatorics. He is deeply passionate about motivating students to study mathematics. This enthusiasm led him to serve as a Patron of The Mathematics Society (TMS). Additionally, he is a board member of the M-inSTEM program organized by the Department of Mathematics. This program focuses on training talented young girls in high school to recognize the importance of mathematics.