CMS NOTES De La SMC
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
How I Learned to Stop Worrying and Love the Bombe: Machine Research and Development and Bletchley Park
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CURVE/open How I learned to stop worrying and love the Bombe: Machine Research and Development and Bletchley Park Smith, C Author post-print (accepted) deposited by Coventry University’s Repository Original citation & hyperlink: Smith, C 2014, 'How I learned to stop worrying and love the Bombe: Machine Research and Development and Bletchley Park' History of Science, vol 52, no. 2, pp. 200-222 https://dx.doi.org/10.1177/0073275314529861 DOI 10.1177/0073275314529861 ISSN 0073-2753 ESSN 1753-8564 Publisher: Sage Publications Copyright © and Moral Rights are retained by the author(s) and/ or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This item cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder(s). The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright holders. This document is the author’s post-print version, incorporating any revisions agreed during the peer-review process. Some differences between the published version and this version may remain and you are advised to consult the published version if you wish to cite from it. Mechanising the Information War – Machine Research and Development and Bletchley Park Christopher Smith Abstract The Bombe machine was a key device in the cryptanalysis of the ciphers created by the machine system widely employed by the Axis powers during the Second World War – Enigma. -
VISIT to BLETCHLEY PARK
REPORT of STAR GROUP – VISIT to BLETCHLEY PARK It was 8-30 on the damp drizzly Monday morning of 5th October when our intrepid group of bleary-eyed third-agers left Keyworth to visit the former codebreaking and cipher centre at Bletchley Park. As we progressed south along the M1 motorway the weather started to clear and by the time we arrived in Milton Keynes the rain and drizzle had stopped. For me the first stop was a cup of coffee in the Block C Visitor Centre. We moved out of the Visitor Centre and towards the lake. We were told that many a wartime romantic coupling around this beautiful lake had led to marriage. The beautiful Bletchley Park Lake So… Moving on. We visited the Mansion House with it’s curious variety of styles of architecture. The original owners of the estate had travelled abroad extensively and each time they returned home they added an extension in the styles that they visited on their travels. The Mansion House At the Mansion we saw the sets that had been designed for the Film “The Imitation Game.” The attention to detail led one to feel that you were back there in the dark days of WWII. History of The Mansion Captain Ridley's Shooting Party The arrival of ‘Captain Ridley's Shooting Party’ at a mansion house in the Buckinghamshire countryside in late August 1938 was to set the scene for one of the most remarkable stories of World War Two. They had an air of friends enjoying a relaxed weekend together at a country house. -
Permutation Groups Containing a Regular Abelian Subgroup: The
PERMUTATION GROUPS CONTAINING A REGULAR ABELIAN SUBGROUP: THE TANGLED HISTORY OF TWO MISTAKES OF BURNSIDE MARK WILDON Abstract. A group K is said to be a B-group if every permutation group containing K as a regular subgroup is either imprimitive or 2- transitive. In the second edition of his influential textbook on finite groups, Burnside published a proof that cyclic groups of composite prime-power degree are B-groups. Ten years later in 1921 he published a proof that every abelian group of composite degree is a B-group. Both proofs are character-theoretic and both have serious flaws. Indeed, the second result is false. In this note we explain these flaws and prove that every cyclic group of composite order is a B-group, using only Burnside’s character-theoretic methods. We also survey the related literature, prove some new results on B-groups of prime-power order, state two related open problems and present some new computational data. 1. Introduction In 1911, writing in §252 of the second edition of his influential textbook [6], Burnside claimed a proof of the following theorem. Theorem 1.1. Let G be a transitive permutation group of composite prime- power degree containing a regular cyclic subgroup. Either G is imprimitive or G is 2-transitive. An error in the penultimate sentence of Burnside’s proof was noted in [7, page 24], where Neumann remarks ‘Nevertheless, the theorem is certainly true and can be proved by similar character-theoretic methods to those that Burnside employed’. In §3 we present the correct part of Burnside’s arXiv:1705.07502v2 [math.GR] 11 Jun 2017 proof in today’s language. -
The First Americans the 1941 US Codebreaking Mission to Bletchley Park
United States Cryptologic History The First Americans The 1941 US Codebreaking Mission to Bletchley Park Special series | Volume 12 | 2016 Center for Cryptologic History David J. Sherman is Associate Director for Policy and Records at the National Security Agency. A graduate of Duke University, he holds a doctorate in Slavic Studies from Cornell University, where he taught for three years. He also is a graduate of the CAPSTONE General/Flag Officer Course at the National Defense University, the Intelligence Community Senior Leadership Program, and the Alexander S. Pushkin Institute of the Russian Language in Moscow. He has served as Associate Dean for Academic Programs at the National War College and while there taught courses on strategy, inter- national relations, and intelligence. Among his other government assignments include ones as NSA’s representative to the Office of the Secretary of Defense, as Director for Intelligence Programs at the National Security Council, and on the staff of the National Economic Council. This publication presents a historical perspective for informational and educational purposes, is the result of independent research, and does not necessarily reflect a position of NSA/CSS or any other US government entity. This publication is distributed free by the National Security Agency. If you would like additional copies, please email [email protected] or write to: Center for Cryptologic History National Security Agency 9800 Savage Road, Suite 6886 Fort George G. Meade, MD 20755 Cover: (Top) Navy Department building, with Washington Monument in center distance, 1918 or 1919; (bottom) Bletchley Park mansion, headquarters of UK codebreaking, 1939 UNITED STATES CRYPTOLOGIC HISTORY The First Americans The 1941 US Codebreaking Mission to Bletchley Park David Sherman National Security Agency Center for Cryptologic History 2016 Second Printing Contents Foreword ................................................................................ -
Letters from William Burnside to Robert Fricke: Automorphic Functions, and the Emergence of the Burnside Problem
LETTERS FROM WILLIAM BURNSIDE TO ROBERT FRICKE: AUTOMORPHIC FUNCTIONS, AND THE EMERGENCE OF THE BURNSIDE PROBLEM CLEMENS ADELMANN AND EBERHARD H.-A. GERBRACHT Abstract. Two letters from William Burnside have recently been found in the Nachlass of Robert Fricke that contain instances of Burnside's Problem prior to its first publication. We present these letters as a whole to the public for the first time. We draw a picture of these two mathematicians and describe their activities leading to their correspondence. We thus gain an insight into their respective motivations, reactions, and attitudes, which may sharpen the current understanding of professional and social interactions of the mathemat- ical community at the turn of the 20th century. 1. The simple group of order 504 { a first meeting of minds Until 1902, when the publication list of the then fifty-year-old William Burnside already encompassed 90 papers, only one of these had appeared in a non-British journal: a three-page article [5] entitled \Note on the simple group of order 504" in volume 52 of Mathematische Annalen in 1898. In this paper Burnside deduced a presentation of that group in terms of generators and relations,1 which is based on the fact that it is isomorphic to the group of linear fractional transformations with coefficients in the finite field with 8 elements. The proof presented is very concise and terse, consisting only of a succession of algebraic identities, while calculations in the concrete group of transformations are omitted. In the very same volume of Mathematische Annalen, only one issue later, there can be found a paper [18] by Robert Fricke entitled \Ueber eine einfache Gruppe von 504 Operationen" (On a simple group of 504 operations), which is on exactly the same subject. -
Introduction to Representation Theory
STUDENT MATHEMATICAL LIBRARY Volume 59 Introduction to Representation Theory Pavel Etingof, Oleg Golberg, Sebastian Hensel, Tiankai Liu, Alex Schwendner, Dmitry Vaintrob, Elena Yudovina with historical interludes by Slava Gerovitch http://dx.doi.org/10.1090/stml/059 STUDENT MATHEMATICAL LIBRARY Volume 59 Introduction to Representation Theory Pavel Etingof Oleg Golberg Sebastian Hensel Tiankai Liu Alex Schwendner Dmitry Vaintrob Elena Yudovina with historical interludes by Slava Gerovitch American Mathematical Society Providence, Rhode Island Editorial Board Gerald B. Folland Brad G. Osgood (Chair) Robin Forman John Stillwell 2010 Mathematics Subject Classification. Primary 16Gxx, 20Gxx. For additional information and updates on this book, visit www.ams.org/bookpages/stml-59 Library of Congress Cataloging-in-Publication Data Introduction to representation theory / Pavel Etingof ...[et al.] ; with historical interludes by Slava Gerovitch. p. cm. — (Student mathematical library ; v. 59) Includes bibliographical references and index. ISBN 978-0-8218-5351-1 (alk. paper) 1. Representations of algebras. 2. Representations of groups. I. Etingof, P. I. (Pavel I.), 1969– QA155.I586 2011 512.46—dc22 2011004787 Copying and reprinting. Individual readers of this publication, and nonprofit libraries acting for them, are permitted to make fair use of the material, such as to copy a chapter for use in teaching or research. Permission is granted to quote brief passages from this publication in reviews, provided the customary acknowledgment of the source is given. Republication, systematic copying, or multiple reproduction of any material in this publication is permitted only under license from the American Mathematical Society. Requests for such permission should be addressed to the Acquisitions Department, American Mathematical Society, 201 Charles Street, Providence, Rhode Island 02904- 2294 USA. -
Docib: 3853634
DOCib: 3853634 Before BOURBON: American and British COMINT Efforts against Russia and the Soviet Union before 1945 MICHAEL L. PETERSON INTRODUCTION ~BOURBON was the·formally assigned covername for a joint American-British COMINT proje<:t to target the Soviet Union after World War II. But it quickly came to be used as a covername for the target country itself. This was because, from the beginning of the project in August 1945 until June 1946, the project was compartmented. ~Why, looking back from the 1990s, would the Soviet problem be compartmented? The simple answer is that Russia was an ally of the United States and Great Britain, and allies were not supposed to be listening in on each other's communications. Nevertheless, what started out as policy quickly became habit. Correspondence produced several years after the project title was formaJly cance1led continued to refer to the "BOURBON problem.n It wasn't the Soviet Navy, it was the "BOURBON Navy." Those weren't Soviet or even Russian callsigns, those were "BOURBON callsigns," and so on. -('Ss0S~BOURBON is believed to be the first organized, collaborative, cryptologic attack on the Soviet Union, although, ~s we will see, the Army's Signal Intelligence Service (forerunner to the Army Security Agency) actually assigned two cryptanalysts full time to the Soviet diplomatic problem in 1943.1 ~0SiQ!But this story, .. Before BOURBON," is about the earJiest documented American and British ventures against Imperial Russia and the Soviet Union. It should come as no surprise to anyone that the British, who were experts in this business for a couple of hundred years, had been reading Imperial Russian diplomatic correspondence since the eighteenth century. -
Churchill's Diplomatic Eavesdropping and Secret Signals Intelligence As
CHURCHILL’S DIPLOMATIC EAVESDROPPING AND SECRET SIGNALS INTELLIGENCE AS AN INSTRUMENT OF BRITISH FOREIGN POLICY, 1941-1944: THE CASE OF TURKEY Submitted for the Degree of Ph.D. Department of History University College London by ROBIN DENNISTON M.A. (Oxon) M.Sc. (Edin) ProQuest Number: 10106668 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest. ProQuest 10106668 Published by ProQuest LLC(2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. Microform Edition © ProQuest LLC. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 2 ABSTRACT Churchill's interest in secret signals intelligence (sigint) is now common knowledge, but his use of intercepted diplomatic telegrams (bjs) in World War Two has only become apparent with the release in 1994 of his regular supply of Ultra, the DIR/C Archive. Churchill proves to have been a voracious reader of diplomatic intercepts from 1941-44, and used them as part of his communication with the Foreign Office. This thesis establishes the value of these intercepts (particularly those Turkey- sourced) in supplying Churchill and the Foreign Office with authentic information on neutrals' response to the war in Europe, and analyses the way Churchill used them. -
The Characters and Commutators of Finite Groups
THE CHARACTERS AND COMMUTATORS OF FINITE GROUPS By TIM W. BONNER A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2009 1 °c 2009 Tim W. Bonner 2 ACKNOWLEDGMENTS I am sincerely grateful to my adviser, Alexandre Turull. With unyielding patience and constant support, he has been integral in my academic and personal growth. I feel indebted to have been his student, and I am fortunate to know such an inspiring individual. I also will forever appreciate the encouragement of my family. Over the past six years, my parents and sister have responded to each step forward and every setback with calm assurance. Finally, my wife, Emily, has witnessed it all only a glance away, and this work undeniably bears the steady strength of her hand. 3 TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................. 3 LIST OF TABLES ..................................... 5 ABSTRACT ........................................ 6 CHAPTER 1 INTRODUCTION .................................. 8 1.1 Products of Commutators ........................... 8 1.2 Further Generation Problems ......................... 9 1.2.1 Products of Conjugacy Classes ..................... 9 1.2.2 Products of Characters ......................... 10 1.3 The Taketa Problem .............................. 11 2 MATHEMATICAL PRELIMINARIES FOR CHAPTERS 3 AND 4 ....... 13 3 PRODUCTS OF COMMUTATORS AND BARDAKOV'S CONJECTURE ... 17 3.1 A Character Identity of Burnside ....................... 18 3.2 Analysis and Results .............................. 21 3.3 Bardakov's Conjecture ............................. 26 4 PRODUCTS OF CONJUGACY CLASSES AND CHARACTERS ........ 28 4.1 Conjugacy Class Covering Numbers ...................... 28 4.2 Comparison with Previous Bounds ...................... 33 4.3 Character Covering Numbers ........................ -
Regular Permutation Groups and Cayley Graphs Cheryl E Praeger University of Western Australia
Regular permutation groups and Cayley graphs Cheryl E Praeger University of Western Australia 1 What are Cayley graphs? Group : G with generating set S = s, t, u, . 1 { } Group elements: ‘words in S’ stu− s etc vertices: group elements Cayley graph: Cay(G, S) edges: multiplication from S 2 What are Cayley graphs? If S inverse closed: s S s 1 S ∈ ⇐⇒ − ∈ Cayley graph Cay(G, S): may use undirected edges 3 Some reasonable questions Where: do they arise in mathematics today? Where: did they originate? What: kinds of groups G give interesting Cayley graphs Cay(G, S)? Which graphs: arise as Cayley graphs? Does it matter: what S we choose? Are: Cayley graphs important and why? And: what about regular permutation groups? Let’s see how I go with answers! 4 In Topology: Embedding maps in surfaces Thanks to Ethan Hein: flickr.com 5 Computer networks; experimental layouts (statistics) Thanks to Ethan Hein: flickr.com and Jason Twamley 6 Random walks on Cayley graphs Applications: from percolation theory to group computation How large n: g ‘approximately random’ in G? Independence? Method: for random selection in groups – underpins randomised algorithms for group computation (Babai, 1991) 7 Fundamental importance for group actions in combinatorics and geometry Iwilldescribe: Regular permutation groups Origins of Cayley graphs Links with group theory Some recent work and open problems on primitive Cayley graphs 8 Permutation groups Permutation : of set Ω, bijection g :Ω Ω Symmetric group of all permutations→ of Ω group Sym (Ω): under composition, for -
History of Mathematics
SIGMAA – History of Mathematics Joint meeting of: British Society for the History of Mathematics Canadian Society for the History and Philosophy of Mathematics History of Mathematics Special Interest Group of the MAA (HOMSIGMAA) Philosophy of Mathematics Special Interest Group of the MAA (POMSIGMAA) Marriott Wardman Park, Washington, D.C. Wednesday, August 5 8:20 MAA Centennial Lecture #1 - Room: Salon 2/3 9:30 Hedrick Lecture #1 - Room: Salon 2/3 Session TCPS#1A: History of Mathematics – Room: Washington 4 Moderator: Amy Ackerberg-Hastings 10:30 Amy Shell-Gellasch, Montgomery College, Maryland Ellipsographs: Drawing Ellipses and the Devices in the Smithsonian Collection 11:00 Peggy Aldrich Kidwell, National Museum of American History, Smithsonian Institution Engaging Minds – Charter Members of the MAA and the Material Culture of American Mathematics 11:30 Florence Fasanelli The History of Mathematics in Washington, D.C. Session TCPS#1B: History of Mathematics – Room: Washington 5 Moderator: Danny Otero 10:30 Cathleen O’Neil Eisenhower, the Binomial Theorem, and the $64,000 Question 11:00 S. Roberts John Horton Conway: Certainly a Piece of History 11:30 E. Donoghue A Pair of Early MAA Presidents = A Pair of Mathematics Historians: Florian Cajori and David Eugene Smith 12:00 Lunch Break Session TCPS#1C: History and Philosophy of Mathematics – Room: Washington 4 Moderator: Jim Tattersall 1:00 Charles Lindsey Doing Arithmetic in Medieval Europe 1:30 Travis D. Williams, University of Rhode Island Imagination and Reading the Third Dimension in Early Modern Geometry 2:00 Christopher Baltus, SUNY Oswego The Arc Rampant in 1673: an Early Episode in the History of Projective Geometry 2:30 Andrew Leahy William Brouncker’s Rectification of the Semi-Cubical Parabola Session TCPS#1D: History and Philosophy of Mathematics – Room: Washington 5 Moderator: Dan Sloughter 1:30 Ann Luppi von Mehren, Arcadia University Inspiration for Elementary Mathematics Descriptions from a “Heritage” Reading (in the sense of Grattan-Guinness) of “On the Nonexistent” by Gorgias 2:00 Thomas Q. -
Introduction to Representation Theory by Pavel Etingof, Oleg Golberg
Introduction to representation theory by Pavel Etingof, Oleg Golberg, Sebastian Hensel, Tiankai Liu, Alex Schwendner, Dmitry Vaintrob, and Elena Yudovina with historical interludes by Slava Gerovitch Licensed to AMS. License or copyright restrictions may apply to redistribution; see http://www.ams.org/publications/ebooks/terms Licensed to AMS. License or copyright restrictions may apply to redistribution; see http://www.ams.org/publications/ebooks/terms Contents Chapter 1. Introduction 1 Chapter 2. Basic notions of representation theory 5 x2.1. What is representation theory? 5 x2.2. Algebras 8 x2.3. Representations 9 x2.4. Ideals 15 x2.5. Quotients 15 x2.6. Algebras defined by generators and relations 16 x2.7. Examples of algebras 17 x2.8. Quivers 19 x2.9. Lie algebras 22 x2.10. Historical interlude: Sophus Lie's trials and transformations 26 x2.11. Tensor products 30 x2.12. The tensor algebra 35 x2.13. Hilbert's third problem 36 x2.14. Tensor products and duals of representations of Lie algebras 36 x2.15. Representations of sl(2) 37 iii Licensed to AMS. License or copyright restrictions may apply to redistribution; see http://www.ams.org/publications/ebooks/terms iv Contents x2.16. Problems on Lie algebras 39 Chapter 3. General results of representation theory 41 x3.1. Subrepresentations in semisimple representations 41 x3.2. The density theorem 43 x3.3. Representations of direct sums of matrix algebras 44 x3.4. Filtrations 45 x3.5. Finite dimensional algebras 46 x3.6. Characters of representations 48 x3.7. The Jordan-H¨oldertheorem 50 x3.8. The Krull-Schmidt theorem 51 x3.9.