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VII.—Entropic Functions for Linear Algebras*

Published online by Cambridge University Press:  14 February 2012

I. M. H. Etherington
Affiliation:
University of Edinburgh

Synopsis

The function ɸx = log x satisfies the functional equation ɸxy = λɸx + μɸy + ϰ, where in this case x, y are complex variables, λ = μ = i, and ϰ = 2πi, o or − 2πi according as σ < − π, − π < σ < π, π < σ, where σ = arg x + arg y. Generalizing this situation, let A be a linear algebra with basis e1, …, en over the real or complex field and let ɸx be a complexvalued function of the hypercomplex variable x = Σξiei, i.e. of the n real or complex variables ξi. Assume that the gradient ∂ɸx, i.e. the column vector of partial derivatives {∂ɸx/∂ξi}, exists at a general point of A. Then ɸx is called an entropic function if it satisfies a functional equation of the above-mentioned form and obeys certain other postulates, ϰ being a step function of the two hypercomplex variables. Values of the constants λ, μ (complex numbers, not both zero) for which a solution exists are entropic roots of A. They are usually discrete.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1958

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References

References to Literature

Albert, A. A., 1942. “Non-associative algebras: I. Fundamental concepts and isotopy”, Ann. Math., 43, 685707.Google Scholar
Cauchy, A. L., 1821. Analyse Algébrique. Paris. [Œuvres (2), 3, pp. 104, 226.]Google Scholar
Etherington, I. M. H., 1940. “Commutative train algebras of ranks 2 and 3”, J. Lond. Math. Soc., 15, 136149; 20, 238.—(Quoted as “C.T.A.”)Google Scholar
Etherington, I. M. H., 1941. “Special train algebras”, Quart. J. Math., 12, 18.—(“S.T.A.”)Google Scholar
Etherington, I. M. H., 1945. “Transposed algebras”, Proc. Edin. Math. Soc., (2) 7, 104121.— (“T.A.”)CrossRefGoogle Scholar
Etherington, I. M. H., 1949. “Non-associative arithmetics”, Proc. Roy. Soc. Edin., A, 62, 442453.—(“N.A.”)Google Scholar
Etherington, I. M. H., 1951. “Non-commutative train algebras of ranks 2 and 3“, Proc. Lond. Math. Soc., (2) 52, 241252—(“N.C.T.A.”)Google Scholar
Etherington, I. M. H., 1954. “Entropic functions of non-associative algebras”, Proc Int. Congr. Math., Amsterdam, 2, 1819.Google Scholar
Etherington, I. M. H., 1955 “Theory of indices for non-associative algebra”, Proc Roy. Soc Edin., A, 64, 150160.—(“T.I.N.A.”)Google Scholar
Minc, H., 1957. “Index polynomials and bifurcating root-trees”, Proc. Roy. Soc. Edin., A, 64, 319341.Google Scholar
Rees, D., 1949. “The nuclei of non-associative division algebras”, Proc. Camb. Phil. Soc., 46, 118.Google Scholar