arXiv subjects
Publications and source records attributed to Yosafat E. P. Pangalela.
In this article, we present a new method to study relative Cuntz-Krieger algebras for higher-rank graphs. We only work with edges rather than paths of arbitrary degrees. We then use this method to simplify the existing results about relative Cuntz-Krieger algebras. We also give applications to study ideals and quotients of Toeplitz algebras.
In this article, we introduce Cohn path algebras of higher-rank graphs. We prove that for a higher-rank graph $Λ$, there exists a higher-rank graph $TΛ$ such that the Cohn path algebra of $Λ$ is isomorphic to the Kumjian-Pask algebra of $TΛ$. We then use this isomorphism and properties of Kumjian-Pask algebras to study Cohn path algebras. This includes proving a uniqueness theorem for Cohn path algebras.
We extend the the definition of Kumjian-Pask algebras to include algebras associated to finitely aligned higher-rank graphs. We show that these Kumjian-Pask algebras are universally defined and have a graded uniqueness theorem. We also prove the Cuntz-Kreiger uniqueness theorem; to do this, we use a groupoid approach. As a consequence of the graded uniqueness theorem, we show that every Kumjian-Pask algebra is isomorphic to the Steinberg algebra associated to its boundary path groupoid. We then use Steinberg algebra results to prove the Cuntz-Kreiger uniqueness theorem and also to characterize simplicity and basic simplicity.
For a real normed space $X$, we study the $n$-dual space of $\left(X,\left\Vert \cdot \right\Vert \right) $ and show that the space is a Banach space. Meanwhile, for a real normed space $X$ of dimension $d\geq n$ which satisfies property (G), we discuss the $n$-dual space of $\left(X,\left\Vert \cdot,\ldots,\cdot \right\Vert _{G}\right) $, where $% \left\Vert \cdot,\ldots,\cdot \right\Vert _{G}$ is the Gähler $n$% -norm. We then investigate the relationship between the $n$-dual space of $% \left(X,\left\Vert \cdot \right\Vert \right) $ and the $n$-dual space of $% \left(X,\left\Vert \cdot,\ldots,\cdot \right\Vert _{G}\right) $. We use this relationship to determine the $n$-dual space of $\left(X,\left\Vert \cdot,\ldots,\cdot \right\Vert _{G}\right) ~$and show that the space is also a Banach space.
For a row-finite higher-rank graph Λ, we construct a higher-rank graph TΛ such that the Toeplitz algebra of Λ is isomorphic to the Cuntz-Krieger algebra of TΛ. We then prove that the higher-rank graph TΛ is always aperiodic and use this fact to give another proof of a uniqueness theorem for the Toeplitz algebras of higher-rank graphs.