An open set of 4×4 embeddable matrices whose principal logarithm is not a Markov generator

A Markov matrix is embeddable if it can represent a homogeneous continuous-time Markov process. It is well known that if a Markov matrix has real and pairwise-different eigenvalues, then the embeddability can be determined by checking whether its principal logarithm is a rate matrix or not. The same...

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Detalles Bibliográficos
Autores: Casanellas Rius, Marta|||0000-0002-1724-8358, Fernández Sánchez, Jesús|||0000-0002-7062-8042, Roca Lacostena, Jordi|||0000-0003-1651-9504
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/366197
Acceso en línea:https://hdl.handle.net/2117/366197
https://dx.doi.org/10.1080/03081087.2020.1854165
Access Level:acceso abierto
Palabra clave:Algebras, Linear
Multilinear algebra
Matrices
Markov processes
Markov matrix
Markov generator
Embedding problem
Rate identifiability
Àlgebra lineal
Àlgebra multilineal
Matrius (Àlgebra)
Markov, Processos de
Classificació AMS::15 Linear and multilinear algebra
matrix theory
Classificació AMS::60 Probability theory and stochastic processes::60J Markov processes
Àrees temàtiques de la UPC::Matemàtiques i estadística::Àlgebra::Àlgebra lineal i multilineal
Àrees temàtiques de la UPC::Matemàtiques i estadística::Anàlisi matemàtica
Descripción
Sumario:A Markov matrix is embeddable if it can represent a homogeneous continuous-time Markov process. It is well known that if a Markov matrix has real and pairwise-different eigenvalues, then the embeddability can be determined by checking whether its principal logarithm is a rate matrix or not. The same holds for Markov matrices that are close enough to the identity matrix. In this paper we exhibit open sets of Markov matrices that are embeddable and whose principal logarithm is not a rate matrix, thus proving that the principal logarithm test above does not suffice generically.