{"product_id":"gabor-szego-collected-papers-1945-1972-von-gabor-p-szego","title":"Gabor Szegö: Collected Papers","description":"1. 1. Definition of L-forms. In the years 1907-1911 O. Toeplitz [21, 22, 23, 24]* studied a class of quadratic forms whose matrix is of the follO\\\\\"ing type: (Ll) C-2 C_I Co C-n-I Cn-I The elements Cn are given complex constants. Toeplitz designated these forms as L-forms and investigated in detail their relation to the analytic function defined in a neighborhood of the unit circle by the Laurent series 2; C z\", n = n - 00, . . . , 00; this series is assumed to be convergent in a certain circular ring rl \u0026lt; I z I \u0026lt; r2, rl \u0026lt; 1 \u0026lt; r2. It is obvious that these matrices are connected with the infinite cyclic group, just as the finite cyclic matrix CO CI C2 C Co CI n r (1. 2) Cn-I C Co n L. c, c, Co is associated with the finite cyclic group. The main result of Toeplitz is that the spectrum of the L-form is identical with the complex values the Laurent series assumes on the unit circle I z I = 1. 1. 2. Hermitian forms. The case C = en is of particular importance; the n matrix (1. 1) is in this case a Hermitian one and the associated Laurent series i8 represents a real function f(8) on the unit circle z = e , -'II\" ~ 8 \u0026lt; '11\".\u003cdiv class=\"aw-variant-hidden-subtitle-div\" id=\"aw-variant-subtitle-9781461257875\"\u003e\u003ch3\u003e1945–1972\u003c\/h3\u003e\u003c\/div\u003e","brand":"Libri","offers":[{"title":"Softcover - 9781461257875","offer_id":39417111117917,"sku":"9781461257875","price":53.49,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0940\/0622\/files\/237f16f2-5aa4-47c6-a286-8c2ee25e7365.jpg?v=1774757486","url":"https:\/\/shop.autorenwelt.de\/en\/products\/gabor-szego-collected-papers-1945-1972-von-gabor-p-szego","provider":"Autorenwelt Shop","version":"1.0","type":"link"}