GAUGE TORSION GRAVITY, STRING THEORY, and ANTISYMMETRIC TENSOR INTERACTIONS a Dissertation Submitted to the Graduate Faculty Of
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GAUGE TORSION GRAVITY, STRING THEORY, AND ANTISYMMETRIC TENSOR INTERACTIONS A Dissertation Submitted to the Graduate Faculty of the North Dakota State University of Agriculture and Applied Science By Terry Glenn Pilling In Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Department: Physics April 2002 Fargo, North Dakota Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number: 3103621 UMI UMI Microform 3103621 Copyright 2003 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1346 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. North Dakota State University Graduate School Title GAUGE TORSION GRAVITY. STRING THEORY. AMD ANTISYMMETRIC TENSOR INTERACTIONS By TERRY GLENN PILLING The Supervisory Committee certifies that this disquisition complies with North Dakota State University’s regulations and meets the accepted standards for the degree of DOCTOR OF PHILOSOPHY SUPERVISORY COMMITTEE: J l k Approved by Department Chair: Date Signature Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ABSTRACT Pilling, Terry Glenn, Ph.D., Department of Physics, College of Science and Mathemat ics, North Dakota State University, April 2002. Gauge Torsion Gravity, String Theory, and Antisymmetric Tensor Interactions. Major Professor: Dr. Patrick F. Kelly. The antisymmetric tensor field is derived in the context of general relativity with torsion as well as the context of string theory. The interaction between antisymmetric tensor fields and fermion fields is examined. The tree level scattering amplitude and the differential and total cross section for massless fermions are derived. The one-loop contribution of torsion exchange to the fermion anomalous magnetic moment is shown to present a solution to a recent problem with the standard model of particle physics. The experimental discrepancy is used to place an upper bound on the torsion coupling to matter. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGMENTS I would like to thank my adviser, Dr. Patrick Kelly, who invited me to North Dakota State University and has been an inspiration and a friend. I am very grateful to the faculty and fellow graduate students. In particular, I am indebted to Dr. Richard Hammond, Patty Hartsoch, Scott Atkins, Feng Hong, Nathan Schoenack, Bin Lu, Tim Storsved, Liess Vantine, and Darren Evans for their assistance and friendship. Special thanks to Bonnie Cooper for meticulously reading the manuscript. Her detailed comments and suggestions have improved this dissertation immensely. Thanks to Dave Hornidge, Trevor Fulton, Darren White, and Derek Harnett for their valued friendship, support, humor, and daily political debates via email. I thank Glenn and Linda Pilling, Rick Pilling, Tammy and Wes Schock, as well as Tyler Schock and Danielle Schock for their love and interest throughout this long trek. Finally, I thank Melanie for her love, support, and amazing patience. Without her, the completion of this dissertation would not have been possible. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS ABSTRACT ............................................................................................................................ iii ACKNOWLEDGMENTS............................................................... iv LIST OF TABLES .................................................................................................................. xi LIST OF FIGURES ........................................................................................................... xii 1. INTRODUCTION ............................................................................................................ 1 2. EINSTEIN-CARTAN GRAVITY ............................................................ 4 2.1. Riemannian manifolds and Cartan’s equations .......................................... 4 2.1.1. The Yang-Mills equations ................................................................... 9 2.1.2. Tensor form ulation ................................................................................ 13 2.2. General relativity , ............................................................................................... 19 2.3. Torsion ..................................................................................... 21 2.3.1. Non-propagating torsion ...................................................................... 26 2.3.2. Propagating torsion ................................................................................ 27 3. GAUGE TORSION G R A V IT Y .................................................................................... 30 3.1. Gauge theories in particle physics .................................................................. 30 3.1.1. Electrodynamic gauge theory ............................................................ 31 3.1.2. Yang-Mills gauge theory ...................................................................... 39 3.2. Gauge theory of gravity ................................................................................... 46 3.2.1. Poincare transformations ...................................................................... 48 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 4. STRING THEORY...................................................................................................... 60 4.1. Introduction ........................................................................................................... 61 4.2. Kalb-Ramond field .............................................................................................. 64 4.2.1. Free point particles and s t r in g s ........................................................ 64 4.2.2. Interacting point particles and strings .............................................. 71 4.2.3. The antisymmetric tensor field .............................................. 75 4.2.4. Properties of the antisymmetric tensor field .................................. 80 5. THE ANTISYMMETRIC TENSOR INTERACTION....................................... 82 5.1. Feynman rules for the Kalb-Ramond field ...................................................... 82 5.2. Tree-level torsion exchange ................................................................................. 86 5.2.1. Scattering amplitude and cross s e c tio n ........................................... 87 5.3. Fermion anomalous magnetic m om ent ............................................................. 91 5.3.1. The g — 2 experimental result ............................................................ 93 5.3.2. The standard model prediction ......................................................... 95 5.4. Torsion contribution to the magnetic m o m e n t ............................................ 97 6. SUMMARY, CONCLUSIONS, AND FUTURE PROSPECTS ....................... 106 6.1. Summary ............................................................................................................... 106 6.2. Future id e a s ............................................................................................................ 107 6.2.1. Quadratic actions ................................................................................... 107 6.2.2. Dual variables .......................................................................................... 108 6.2.3. Torsion as an effective t h e o r y ............................................................ 110 6.2.4. Topological effects ................................................................................ 117 REFERENCES...................................................................................................................... 118 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. APPENDIX A. FIELD THEORY CONVENTIONS.................................................. 124 A.l. General definitions .............................................................................................. 124 A. 1.1. Pauli m atrices ....................................................................................... 124 A.2. Spinor definitions and form ulae ...................................................................... 126 A.2.1. Gamma m a tric e s .................................................................................... 126 A.2.2. Weyl, Dirac, and Majorana s p in o r s .................................................. 129 A.2.3. Spinor in d ices ........................................................................................... 130 A.2.4. Fierz identities ....................................................................................... 131 A.3. Free field propagators . .................................................................................... 134 A.4. Renormalization formulae ................................................................................. 137 A.4.1. Dimensional regularization.................................................................... 137 APPENDIX B. INTRODUCTION