{"id":259552,"date":"2026-07-13T17:04:04","date_gmt":"2026-07-13T14:04:04","guid":{"rendered":"https:\/\/1kitap1.com\/en\/essential-algebraic-number-theory-ivan-fesenko\/"},"modified":"2026-07-13T17:04:04","modified_gmt":"2026-07-13T14:04:04","slug":"essential-algebraic-number-theory-ivan-fesenko","status":"publish","type":"post","link":"https:\/\/1kitap1.com\/en\/essential-algebraic-number-theory-ivan-fesenko\/","title":{"rendered":"Essential Algebraic Number Theory &#8211; Ivan Fesenko"},"content":{"rendered":"<figure style=\"text-align:center;margin:0 auto 1.5em;\"><img decoding=\"async\" src=\"https:\/\/1kitap1.com\/en\/wp-content\/uploads\/2026\/07\/6822bfab998fe6b7.jpg\" alt=\" - Unknown book cover\" style=\"max-width:300px;width:100%;height:auto;box-shadow:0 4px 12px rgba(0,0,0,.25);border-radius:4px;\"\/><\/figure>\n<p>Putting Y = X\u22121 and performing the calculations in the \ufb01eld L((Y)), we consequently deduce f(X) = Y \u2212p(1+ap\u22121Y +\u00b7\u00b7\u00b7+a0Y p), f(X) = Y p 1+ap\u22121Y +\u00b7\u00b7\u00b7+a0Y p \u2261Y p mod Y p+1, X \u2212\u03c3i(\u03c0L) = 1\u2212\u03c3i(\u03c0L)Y = \u2211 j\u2a7e0 \u03c3i(\u03c0 j L)Y j+1 (because 1\/(1\u2212Y) = \u2211i\u2a7e0Y i in F((Y))). Hence \u2211 j\u2a7e0 p\u22121 \u2211 i=0 \u03c3i(\u03c0 j L)Y j+1 f \u2032\u0000\u03c3i(\u03c0L) \u0001 \u2261Y p mod Y p+1, or TrL\/F \u03c0 j f \u2032(\u03c0L) ! = p\u22121 \u2211 i=0 \u03c3i(\u03c0 j f \u2032\u0000\u03c3i(\u03c0L) \u0001 = ( if 0 \u2a7dj \u2a7dp\u22122, if j = p\u22121, as desired.<\/p>\n<p>\u25a1 PROPOSITION. Let [a] denote the maximal integer \u2a7da. For an integer i \u2a7e0 put j(i) = s+1+[(i\u22121\u2212s)\/p]. Then TrL\/F(\u03c0i LOL) = \u03c0 j(i) Proof. One has f \u2032(\u03c0L) = \u220fp\u22121 i=1 \u0000\u03c0L \u2212\u03c3i(\u03c0L) \u0001 . From the de\ufb01nition of s we deduce \u03c3i(\u03c0L)\/\u03c0L \u22611+i\u03b7\u03c0s mod \u03c0s+1 . Then f \u2032(\u03c0L) = (p\u22121)!(\u2212\u03b7)p\u22121\u03c0(p\u22121)(s+1) \u03b5 with some \u03b5 \u22081+M (p\u22121)(s+1)+1 . Since F = L, for a prime element \u03c0F in F one has the representation \u03c0F = \u03c0 p L\u03b5\u2032 with \u03b5\u2032 \u2208UL.<\/p>\n<p>The previous Lemma implies TrL\/F \u0010 \u03c0 j+s+1 \u03b5j+s+1 \u0011 = ( if 0 \u2a7dj < p\u22121, \u03c0s+1 if j = p\u22121 for \u03b5j+s+1 = (\u03b5\u2032)s+1\/ \u0000(p\u22121)!(\u2212\u03b7)p\u22121\u03b5 \u0001 . Since TrL\/F(\u03c0i F\u03b1) = \u03c0i F TrL\/F(\u03b1), we can choose the units \u03b5j+s+1, for every integer j > 0, such that TrL\/F(\u03c0 j+s+1 \u03b5j+s+1) = 0 if p\u2224(j +1) and = \u03c0s+(j+1)\/p if p|(j +1).<\/p>\n<p>Thus, since the OF-module \u03c0i LOL is generated by \u03c0 j L\u03b5j, j \u2a7ei, we conclude that TrL\/F(\u03c0i LOL) = \u03c0 j(i) \u25a1 13.5. PROPOSITION. Let L\/F be a totally rami\ufb01ed Galois extension of de- gree p = char(F) > 0. Let \u03c0L be a prime element in L. Then \u03c0F = NL\/F\u03c0L is a prime element in F.<\/p>\n<blockquote>\n<p>Series Editors: Shigeru Kanemitsu (Shandong University, PR China &#038; Kerala School of Mathematics, India) Jianya Liu (Shandong University, PR China) Editorial Board Members: R. Balasubramanian (Institute of Mathematical Sciences, India) V. N. Chubarikov (Moscow State University, Russian Federation) Christopher Deninger (Universit\u00e4t M\u00fcnster, Germany) Chaohua Jia (Chinese Academy of Sciences, PR China) H. Niederreiter (RICAM, Austria) Advisory Board: Current Member M. Waldschmidt (Universit\u00e9 Pierre et Marie Curie, France) In Memoriam K. Ramachandra (Tata Institute of Fundamental Research, Mumbai-Bangalore and National Institute of Advanced Studies, Bangalore, India) A. Schinzel (Polish Academy of Sciences, Poland) *For the complete list of the published titles in this series, please visit: www.worldscientific.com\/series\/sntia World Scientific Published by World Scientific Publishing Co.<\/p>\n<p>Pte. Ltd. 5 Toh Tuck Link, Singapore 596224 USA office: 27 Warren Street, Suite 401-402, Hackensack, NJ 07601 UK office: 57 Shelton Street, Covent Garden, London WC2H 9HE Library of Congress Control Number: 2025054220 British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library.<\/p>\n<p>Cover image: Delicate Tension, No. 85 (1923) by Wassily Kandinsky. Public domain. Series on Number Theory and Its Applications \u2014 Vol. 18 ESSENTIAL ALGEBRAIC NUMBER THEORY Copyright \u00a9 2026 by Ivan Fesenko All rights reserved. ISBN 978-981-98-2571-4 (hardcover) ISBN 978-981-98-2681-0 (paperback) ISBN 978-981-98-2572-1 (ebook for institutions) ISBN 978-981-98-2573-8 (ebook for individuals) For any available supplementary material, please visit https:\/\/www.worldscientific.com\/worldscibooks\/10.1142\/14658#t=suppl Desk Editors: Nambirajan Karuppiah\/Lai Fun Kwong Typeset by Stallion Press Email: enquiries@stallionpress.com Printed in Singapore Preface This book is based on courses given in Russia, the UK and China, as well as numerous talks delivered in Germany, Japan, France, and the USA.<\/p>\n<p>The most recent lecture courses were given at Tsinghua University in 2023\u20132024 and at Westlake University in 2025. The material of the \ufb01rst chapter was lectured for over 10 years in the UK. The book offers a fast and relatively easy introduction into the main aspects of algebraic number theory, including its basic aspects, main results about local and global \ufb01elds and of explicit class \ufb01eld theory. The emphasise is on a clear presentation, using as little auxiliary tools from algebra or analysis as possible.<\/p>\n<p>The presentation of this book was motivated by the author\u2019s study and research in generalisations of class \ufb01eld theory such as higher class \ufb01eld theory, anabelian geometry and some topics in the Langlands program. The main aim of the book is the enable the reader to learn central key aspects of the theory and to prepare for research work in modern number theory.<\/p>\n<p>The \ufb01rst chapter is a compact simpli\ufb01ed presentation of core features of alge- braic number \ufb01elds, without using analytic tools. Various properties of algebraic integers are deduced from properties of Dedekind rings.<\/p>\n<\/blockquote>\n<p><em>This is a short excerpt from the opening of &ldquo;&rdquo; by Unknown, quoted for review and introduction purposes. All rights belong to the copyright holders.<\/em><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_85 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/1kitap1.com\/en\/essential-algebraic-number-theory-ivan-fesenko\/#Book_Information\" >Book Information<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/1kitap1.com\/en\/essential-algebraic-number-theory-ivan-fesenko\/#Reading_Word_Statistics\" >Reading &amp; Word Statistics<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/1kitap1.com\/en\/essential-algebraic-number-theory-ivan-fesenko\/#Most_Frequent_Words\" >Most Frequent Words<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/1kitap1.com\/en\/essential-algebraic-number-theory-ivan-fesenko\/#PDF_Download\" >PDF Download<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"Book_Information\"><\/span>Book Information<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><strong>Unique ID:<\/strong> 6822bfab998fe6b7<\/li>\n<li><strong>File Extension:<\/strong> .pdf<\/li>\n<li><strong>File Size:<\/strong> 8,471,158 bytes (8.079 MB)<\/li>\n<li><strong>Title:<\/strong> &#8211;<\/li>\n<li><strong>Author:<\/strong> Unknown<\/li>\n<li><strong>ISBN:<\/strong> 9789819825714, 9789819826810, 9789819825721, 9789819825738<\/li>\n<li><strong>Pages:<\/strong> 286<\/li>\n<li><strong>Language:<\/strong> English (en)<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Reading_Word_Statistics\"><\/span>Reading &amp; Word Statistics<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><strong>Estimated Reading Time:<\/strong> 508.07 minutes<\/li>\n<li><strong>Total Words:<\/strong> 101,615<\/li>\n<li><strong>Total Characters:<\/strong> 526,220<\/li>\n<li><strong>Average Words per Page:<\/strong> 355.3<\/li>\n<li><strong>Average Characters per Page:<\/strong> 1839.93<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Most_Frequent_Words\"><\/span>Most Frequent Words<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>let (841), \ufb01eld (785), \ufb01nite (619), extension (543), gal (512), theory (451), group (419), proof (350), number (341), prime (326), proposition (307), element (301), algebraic (290), class (281), since (281), valuation (277), hence (273), discrete (262), galois (248), every (247), chapter (243), ideal (213), theorem (212), local (207), degree (205), \ufb01elds (198), one (196), mod (196), characteristic (174), corollary (171), case (169), maximal (167), ring (167), residue (162), extensions (161), map (160), polynomial (160), deduce (154), separable (153), using (151), subgroup (151), elements (150), show (149), complete (143), get (141), essential (139), thus (138), lemma (137), positive (136), integer (129), therefore (129), called (128), denote (128), homomorphism (126), norm (122), abelian (121), set (120), obtain (119), respect (118), open (116), char (113), root (108), put (108), order (107), fur (106), unrami\ufb01ed (105), rami\ufb01ed (105), fields (103), places (103), \ufb01rst (102), integral (101), see (99), integers (98), cyclic (98), index (98), implies (98), image (97), de\ufb01ne (96), non-zero (93), now (92), function (92), irreducible (91), product (91), lim (91), de\ufb01ned (89), global (88), assume (88), property (85), follows (84), ideals (83), totally (83), zero (81), topology (81), groups (80), p-adic (78), closed (77), also (76), reciprocity (74), rami\ufb01cation (74), previous (73).<\/p>\n<h2><span class=\"ez-toc-section\" id=\"PDF_Download\"><\/span>PDF Download<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p style=\"text-align:center;\"><a href=\"https:\/\/1kitap1.com\/en\/wp-content\/uploads\/2026\/07\/essential-algebraic-number-theory-ivan-fesenko.pdf\" download rel=\"nofollow\" style=\"display:inline-block;background:#2271b1;color:#ffffff;padding:14px 36px;border-radius:6px;text-decoration:none;font-weight:bold;font-size:1.05em;\">&#11015;&#65039; PDF Download<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Putting Y = X\u22121 and performing the calculations in the \ufb01eld L((Y)), we consequently deduce f(X) = Y \u2212p(1+ap\u22121Y +\u00b7\u00b7\u00b7+a0Y p), f(X) = Y p 1+ap\u22121Y +\u00b7\u00b7\u00b7+a0Y p \u2261Y p mod Y p+1, X \u2212\u03c3i(\u03c0L) = 1\u2212\u03c3i(\u03c0L)Y = \u2211 j\u2a7e0 \u03c3i(\u03c0 j L)Y j+1 (because 1\/(1\u2212Y) = \u2211i\u2a7e0Y i in F((Y))). Hence \u2211 j\u2a7e0 p\u22121 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":259550,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-259552","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-english"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/1kitap1.com\/en\/wp-json\/wp\/v2\/posts\/259552","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/1kitap1.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/1kitap1.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/1kitap1.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/1kitap1.com\/en\/wp-json\/wp\/v2\/comments?post=259552"}],"version-history":[{"count":0,"href":"https:\/\/1kitap1.com\/en\/wp-json\/wp\/v2\/posts\/259552\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/1kitap1.com\/en\/wp-json\/wp\/v2\/media\/259550"}],"wp:attachment":[{"href":"https:\/\/1kitap1.com\/en\/wp-json\/wp\/v2\/media?parent=259552"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/1kitap1.com\/en\/wp-json\/wp\/v2\/categories?post=259552"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/1kitap1.com\/en\/wp-json\/wp\/v2\/tags?post=259552"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}