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Author Eholzer, Wolfgang
Source CiteSeerX
Content type Text
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Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Invariant Space ♦ Modular Set ♦ Certain Modular Unit ♦ Modular Unit ♦ Several Explicit Example ♦ Vector Space ♦ Classi Cation ♦ Non-negative Integer Fourier Coe Cients ♦ Natural Semi-subgroup ♦ Suitable Normal-isation ♦ Fourier Expansion ♦ Usual Action ♦ Rational Number ♦ Rational Vertex Operator Algebra ♦ Nite Subset ♦ Certain Inequality ♦ Conformal Eld Theory
Abstract Characters of rational vertex operator algebras (RVOAs) arising in 2-dim. conformal ¯eld theories often belong (after suitable normal-isation) to the (multiplicative) semigroup E+ of modular units whose Fourier expansions are in q®(1 + q Z¸0[[q]]) for some rational number ®. If even all characters of a RVOA have this property then we have an example of what we call modular sets, i.e. ¯nite subsets of E+ whose elements (additively) span a vector space which is invariant under the usual action of SL(2; Z). The classi¯cation of modular sets and RVOAs seem to be closely related. In this note we prove a stronger version of a certain inequality which allows to compute several explicit examples of modular sets contained in a natural semi-subgroup E ¤ of the semi-group E+ of modular units which have non-negative integer Fourier coe±cients.
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study
Publisher Institution Universitäat Siegen
Publisher Department Fachbereich Mathematik