Beginning in 1974, the fictitious Peter Orno appeared as the author of research papers in mathematics. According to Robert Phelps, the name "P. Orno" is a pseudonym that was inspired by "porno", an abbreviation for "pornography". Orno's short papers have been called "elegant" contributions to functional analysis. Orno's theorem on linear operators is important in the theory ofBanach spaces. Research mathematicians have written acknowledgments that have thanked Orno for stimulating discussions and for Orno's generosity in allowing others to publish his results. The Mathematical Association of America's journals have also published more than a dozen problems whose solutions were submitted in the name of Orno.
Biography
Peter Orno appears as the author of short papers written by an anonymous mathematician; thus "Peter Orno" is a pseudonym. According to Robert R. Phelps, the name "P. Orno" was inspired by "porno", a shortening of "pornography". Orno's papers list his affiliation as the Department of Mathematics at Ohio State University. This affiliation is confirmed in the description of Orno as a "special creation" at Ohio State in Pietsch's History of Banach spaces and linear operators. The publications list of Ohio State mathematician Gerald Edgar includes two items that were published under the name of Orno. Edgar indicates that he published them "as Peter Ørno".
Research
His papers feature "surprisingly simple" proofs and solutions to open problems in functional analysis and approximation theory, according to reviewers from Mathematical Reviews: In one case, Orno's "elegant" approach was contrasted with the previously known "elementary, but masochistic" approach. Peter Orno's "permanent interest and sharp criticism stimulated" the "work" on Lectures on Banach spaces of analytic functions by Aleksander Pełczyński, which includes several of Orno's unpublished results. Tomczak-Jaegermann thanked Peter Orno for his stimulating discussions.
According to Mathematical Reviews, this paper proves the following theorem, which has come to be known as "Orno's theorem": Suppose that E and F are Banach lattices, where F is an infinite-dimensional vector space that contains no Riesz subspace that is uniformly isomorphic to the sequence space equipped with the supremum norm. If each linear operator in the uniform closure of the finite-rank operators from E to F has a Riesz decomposition as the difference of two positive operators, then E can be renormed so that it is an L-space.
According to Mathematical Reviews, Orno proved the following theorem: The series ∑fkunconditionally converges in the Lebesgue space of absolutely integrable functions L1if and only if, for each k and every t, we have fk=akgwk, for some sequence ∈l2, some function g∈L2, and for some orthonormal sequence in L2. Another result is what Joseph Diestel described as the "elegant proof" by Orno of a theorem of Bennet, Maurey and Nahoum.
In this paper, Orno solves an eight-year-old problem posed by Ivan Singer, according to Mathematical Reviews.
Still circulating as an "underground classic", as of 2018 this paper had been cited sixteen times. In it, Orno solved a problem posed by Jonathan M. Borwein. Orno characterized sequentiallyreflexive Banach spaces in terms of their lacking bad subspaces: Orno's theorem states that a Banach spaceX is sequentially reflexive if and only ifthe space of absolutely summable sequences ℓ1 is not isomorphic to a subspace of X.
Problem-solving
Between 1976 and 1982, Peter Orno contributed problems or solutions that appeared in eighteen issues of Mathematics Magazine, which is published by the Mathematical Association of America. In 2006, Orno solved a problem in the American Mathematical Monthly, another peer-reviewed journal of the MAA:
Context
Peter Orno is one of several pseudonymous contributors in the field of mathematics. Other pseudonymous mathematicians active in the 20th century include Nicolas Bourbaki, John Rainwater, M. G. Stanley, and H. C. Enos.
