scholarly journals Leonard pairs having specified end-entries

2015 ◽  
Vol 465 ◽  
pp. 43-64
Author(s):  
Kazumasa Nomura
Keyword(s):  
2019 ◽  
Vol 7 (1) ◽  
pp. 1-19
Author(s):  
Kazumasa Nomura ◽  
Paul Terwilliger

Abstract Let F denote a field and let V denote a vector space over F with finite positive dimension. Consider a pair A, A* of diagonalizable F-linear maps on V, each of which acts on an eigenbasis for the other one in an irreducible tridiagonal fashion. Such a pair is called a Leonard pair. We consider the self-dual case in which there exists an automorphism of the endomorphism algebra of V that swaps A and A*. Such an automorphism is unique, and called the duality A ↔ A*. In the present paper we give a comprehensive description of this duality. In particular,we display an invertible F-linearmap T on V such that the map X → TXT−1is the duality A ↔ A*. We express T as a polynomial in A and A*. We describe how T acts on 4 flags, 12 decompositions, and 24 bases for V.


2014 ◽  
Vol 455 ◽  
pp. 1-21 ◽  
Author(s):  
Kazumasa Nomura
Keyword(s):  

2007 ◽  
Vol 420 (1) ◽  
pp. 51-69 ◽  
Author(s):  
Kazumasa Nomura ◽  
Paul Terwilliger
Keyword(s):  

2004 ◽  
Vol 03 (04) ◽  
pp. 411-426 ◽  
Author(s):  
PAUL TERWILLIGER ◽  
RAIMUNDAS VIDUNAS

Let K denote a field and let V denote a vector space over K with finite positive dimension. We consider an ordered pair of linear transformations A:V→V and A*:V→V which satisfy the following two properties: (i) There exists a basis for V with respect to which the matrix representing A is irreducible tridiagonal and the matrix representing A* is diagonal. (ii) There exists a basis for V with respect to which the matrix representing A* is irreducible tridiagonal and the matrix representing A is diagonal. We call such a pair a Leonard pair on V. Referring to the above Leonard pair, we show there exists a sequence of scalars β,γ,γ*,ϱ,ϱ*,ω,η,η* taken from K such that both [Formula: see text] The sequence is uniquely determined by the Leonard pair provided the dimension of V is at least 4. The equations above are called the Askey–Wilson relations.


2017 ◽  
Vol 533 ◽  
pp. 14-83 ◽  
Author(s):  
Kazumasa Nomura ◽  
Paul Terwilliger
Keyword(s):  

2005 ◽  
Vol 408 ◽  
pp. 19-39 ◽  
Author(s):  
Brian Hartwig
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document