Tatsuro Ito

activity

20032009

P

-and

Q

-polynomial association schemes

40 citations · 144 across the 18 of their papers we have counts for

collaborators

Showing math.RAShow all

5 papers · 1 filter

math.RA2009

An algebra generated by two sets of mutually orthogonal idempotents

Tatsuro Ito, Paul Terwilliger

For a field $F$ and an integer $d \geq 1$ , we consider the universal associative $F$ -algebra $A$ generated by two sets of $d + 1$ mutually orthogonal idempotents. We display four base…

math.RA2008★ 5 cited

Mock Tridiagonal Systems

Tatsuro Ito, Paul Terwilliger

We introduce the notion of a {\it mock tridiagonal system}. This is a generalization of a tridiagonal system in which the irreducibility assumption is replaced by a certain non-van…

math.RA2008★ 10 cited

How to sharpen a tridiagonal pair

Tatsuro Ito, Paul Terwilliger

Let $\F$ denote a field and let $V$ denote a vector space over $\F$ with finite positive dimension. We consider a pair of linear transformations $A : V \to V$ and $A^{*} : V \to V$ that…

math.RA2008★ 19 cited

The Drinfel'd polynomial of a tridiagonal pair

Tatsuro Ito, Paul Terwilliger

Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A : V \to V$ and $A^{*} : V \to V$ that sa…

math.RA2007★ 5 cited

Tridiagonal pairs of Krawtchouk type

Tatsuro Ito, Paul Terwilliger

Let $K$ denote an algebraically closed field with characteristic 0 and let $V$ denote a vector space over $K$ with finite positive dimension. Let $A, A^{*}$ denote a tridiagonal pair…