Document Type


Date of Degree

Summer 2016

Degree Name

PhD (Doctor of Philosophy)

Degree In


First Advisor

Paul Muhly

First Committee Member

Ionut Chifan

Second Committee Member

Raul Curto

Third Committee Member

Oguz Durumeric

Fourth Committee Member

Palle Jorgensen


My research studies algebras of holomorphic functions from $d$-tuples of $n\times n$- matrices, $M_n(\bC)^d$, to $M_n(\bC)$. In particular, I study the holomorphic functions that can be approximated by \emph{polynomial matrix concomitants}, that is polynomial maps from $M_n(\bC)^d$ to $M_n(\bC)$ that satisfy the relationship


f(g^{-1}\fz g) = g^{-1}f(\fz)g


for every $\fz \in M_n(\bC)^d$ and $g\in GL_n(\bC)$. In a sense, these are the polynomial maps that “remember” the structure of the $d$-tuple $\fz$.

My first result is that these holomorphic matrix concomitants can be identified with holomorphic cross sections of certain matrix bundles. A holomorphic matrix bundle is a fibred space in which every fibre is $M_n(\bC)$ and the fibres are glued together in such a way that the total space has a holomorphic structure.

Once the identification between holomorphic cross sections and holomorphic concomitants is established, the structure of the matrix bundle is used to endow the algebra of continuous cross sections with a $C^*$-algebra structure. Then we study the subalgebra of cross sections that can be approximated by polynomial concomitants. By identifying the matrix concomitants with cross sections, we are able to prove interesting results about these algebras.


Functional Analysis, Noncommutative Function Theory


vii, 86 pages


Includes bibliographical references (pages 83-86).


Copyright © 2016 Erin Griesenauer

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