Title
Independent subspace analysis is unique, given irreducibility
Abstract
Independent Subspace Analysis (ISA) is a generalization of ICA. It tries to find a basis in which a given random vector can be decomposed into groups of mutually independent random vectors. Since the first introduction of ISA, various algorithms to solve this problem have been introduced, however a general proof of the uniqueness of ISA decompositions remained an open question. In this contribution we address this question and sketch a proof for the separability of ISA. The key condition for separability is to require the subspaces to be not further decomposable (irreducible). Based on a decomposition into irreducible components, we formulate a general model for ISA without restrictions on the group sizes. The validity of the uniqueness result is illustrated on a toy example. Moreover, an extension of ISA to subspace extraction is introduced and its indeterminacies are discussed.
Year
Venue
Keywords
2007
ICA
irreducible component,general model,isa decomposition,general proof,open question,independent subspace analysis,group size,independent random vector,uniqueness result,random vector
Field
DocType
Volume
Uniqueness,Combinatorics,Irreducible component,Algebra,Subspace topology,Irreducibility,Linear subspace,Multivariate random variable,Independent component analysis,Mathematics,Independence (probability theory)
Conference
4666
ISSN
ISBN
Citations 
0302-9743
3-540-74493-2
10
PageRank 
References 
Authors
0.69
7
2
Name
Order
Citations
PageRank
Harold W. Gutch1454.60
Fabian J. Theis293185.37