Inflectionary invariants for isolated complete intersection curve singularities / Anand P. Patel, Ashvin A. Swaminathan.

Author/creator Patel, Anand P.
Other author Swaminathan, Ashvin A.
Format Electronic
Publication InfoProvidence, RI : AMS, American Mathematical Society, 2023.
Descriptionvii, 99 pages ; 26 cm.
Supplemental ContentFull text available from Ebook Central - Academic Complete
Subjects

SeriesMemoirs of the American Mathematical Society, 0065-9266 ; volume 282, number 1397
Contents Background material -- Defining automatic degeneracy -- Automatic degeneracies of a node -- Automatic degeneracies of higher-order singularities -- Examples of computing automatic degeneracies -- Other enumerative applications.
Abstract "We investigate the role played by curve singularity germs in the enumeration of inflection points in families of curves acquiring singular members. Let N [greater than or equal to] 2, and consider an isolated complete intersection curve singularity germ f : (CN, 0) [arrow] (CN[minus]1, 0). We define a numerical function m [x in a square] [arrow] ADm(2)(f) that naturally arises when counting mth-order weight-2 inflection points with ramification sequence (0, . . . , 0, 2) in a 1-parameter family of curves acquiring the singularity f [equals] 0, and we compute ADm(2)(f) for several interesting families of pairs (f,m). In particular, for a node defined by f : (x, y) [x in a square] [arrow] xy, we prove that ADm (2)(xy) [equals] [x in a square](m[plus]1)4 [x in a square], and we deduce as a corollary that ADm (2)(f) [greater than or equal to] (mult0 [delta symbol]f ) [x in a square](m[plus]1)4 [x in a square] for any f, where mult0 [delta symbol]f is the multiplicity of the discriminant [delta symbol]f at the origin in the deformation space. Significantly, we prove that the function m [x in a square] [arrow] ADm (2)(f)[minus](mult0 [delta symbol]f ) [x in a square](m[plus]1)4 [x in a square] is an analytic invariant measuring how much the singularity "counts as" an inflection point. We prove similar results for weight-2 inflection points with ramification sequence (0, . . . , 0, 1, 1) and for weight-1 inflection points, and we apply our results to solve a number of related enumerative problems"-- Provided by publisher.
Bibliography noteIncludes bibliographical references (pages 97-99).
Access restrictionAvailable only to authorized users.
Technical detailsMode of access: World Wide Web
Genre/formElectronic books.
LCCN 2023013008
ISBN9781470461577 (paperback)
ISBN(pdf)

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