Admissible Fundamental Operators and Models for $\Gamma_{E(3; 3; 1, 1, 1)}$-contraction and $\Gamma_{E(3; 2; 1, 2)}$-contraction
Functional Analysis
2025-11-05 v1
Abstract
We show that for a given pure contraction T7 acting on a Hilbert space H, if (F~1,…,F~6)∈B(DT7∗) with [F~i,F~j]=0,[F~i∗,F~7−j]=[F~j∗,F~7−i],w(F~i∗+F~7−iz)⩽1 and these operators satisfy (F~i∗+F~7−iz)ΘT7(z)=ΘT7(z)(Fi+F7−i∗z)for allz∈D for 1⩽i,j⩽6 for some (F1,…,F6)∈B(DT7) with w(Fi∗+F7−iz)⩽1 for 1⩽i⩽6, then there exists a ΓE(3;3;1,1,1)-contraction (T1,…,T7) such that F1,…,F6 are the fundamental operators of (T1,…,T7) and F~1,…,F~6 are the fundamental operators of (T1∗,…,T7∗). We also prove similar type of result for pure ΓE(3;2;1,2)-contraction. We explicitly construct a ΓE(3;3;1,1,1)-unitary (respectively, a ΓE(3;2;1,2)-unitary) starting from a ΓE(3;3;1,1,1)-contraction (respectively, a ΓE(3;2;1,2)-contraction). Further, we develop functional models for general ΓE(3;3;1,1,1)-isometries (respectively, ΓE(3;2;1,2)-isometries). In particular, we construct Douglas-type and Sz.-Nazy-Foias-type models for ΓE(3;3;1,1,1)-contractions (respectively, ΓE(3;2;1,2)-contractions). Finally, we present a Schaffer-type model for the ΓE(3;3;1,1,1)-isometric dilation (respectively, the ΓE(3;2;1,2)-isometric dilation).
Cite
@article{arxiv.2511.02635,
title = {Admissible Fundamental Operators and Models for $\Gamma_{E(3; 3; 1, 1, 1)}$-contraction and $\Gamma_{E(3; 2; 1, 2)}$-contraction},
author = {Avijit Pal and Bhaskar Paul},
journal= {arXiv preprint arXiv:2511.02635},
year = {2025}
}
Comments
This is the initial version of the paper. Final version will submit soon