物理学经典教材（影印版）：弦论 [String Theory in a Nutshell] pdf epub mobi txt 电子书 下载 在线阅读 2026

内容简介

　　This is a textbook on the collection ofideas categorized under the name of "string theory." This is a large domain that has as its central goal the unification ofallinteractions including gravity. There have been several surges ofprogress in different directions in the past twenty years， and this book tries to give the student ofthe field some of the salientideas.

内页插图

目录

1 Introduction
1.i Prehistory
1.2 The Case for String Theory
1.3 A Stringy Historical Perspective
1.4 Conventions
Bibliography

2 Classical String Theory
2.1 The Point Particle
2.2 Relativistic Strings
2.3 0scillator Expansions
2.3.1 00sed strings
2.3.2 0pen strings
2.3.3 The Virasoro constraints
Bibliography
Exercises

3 Quantization of Bosonic Strings
3.1 Covariant Canonical Quantization
3.2 Light-cone Quantization
3.3 Spectrum of the Bosonic String
3.4 Unoriented Strings
3.4. 1 0pen. strings and Chan-Patonfactors
3.5 Path Integral Quantization
3.6 Topologically Nontrivial World-sheets
3.7 BRST Primer
3.8 BRST in String Theory and the Physical Spectrum
Bibliography
Exercises

4 Conformal Field Theory
4.1 Conformal Transformations
4.1.1 The case oftwo dimensions
4.2 Conformally Invariant Field Theory
4.3 Radial Quantization
4.4 Mode Expansions
4.5 The Virasoro Algebra and the Central Charge
4.6 The Hilbert Space
4.7 The Free Boson
4.8 The Free Fermion
4.9 The Conformal Anomaly
4.10 Representations of the Conformal Algebra
4.11 Affine Current Algebras
4.12 Free Fermions and O(N) Affine Symmetry
4.13 Superconformal Symmetry
4.13.1 N =(1.0)2 SIAperconformal symmetry
4.13.2 N =(2.0)2 superconformal symmetry
4.13.3 N =(4.0)2 superconformal symmetry
4.14 Scalars with Background Charge
4.15 The CFT of Ghosts
4.16 CFT on the Disk
4.16.1 Free massless bosons on the dislc
4.16.2 Free masslessfern竹ions on the dislc
4.16.3 The projective plane
4.17 CFT on the Torus
4.18 Compact Scalars
4.18.1 Modular invariance
4.18.2 Decompaaification
4.18.3 The torus propagator
4.18.4 Marginal deformations
4.18.5 Multiple compaa scalars
4.18.6 Enhanced symmetry and the string Brout-Englert-lliggs effea
4.18.7 T-duality
4.19 Free Fermions on the Torus
4.20 Bosonization
4.20. 1 "Bosonization " of bosonic ghost system
4.21 0rbifolds
……
5 Scattering Amplitudes and 'Vertex Operators
6 Strings in Background Fields
7 Superstrings and Supersymmetry
8 D-branes
9 Compactifications and Supersymmetry Breaking
10 Loop Corrections to String Effective Couplings
11 Duality Connections and Nonperturbative Effects
12 Black Holes and Entropy in String Theory
13 The Bulk／Boundary Correspondence
14 String theroy and Matrix Models

精彩书摘

　　Although I wrote a short textbook in 1997， I have not yet learned my lesson. Therefore， I embarked on a direct confrontation with deadlines that， although not as spectacular as the ones in Polchinski's book， managed to wreak havoc on my academic and personal schedule. i have not even put sufhcient credence in a colleague's statement "it is never too late to stop writing a book." I can only hope now that the result was worth the effort.
　　This is a textbook on the collection of ideas categorized under the name of "string theory." This is a large domain that has as its central goal the unification of all interactions induding gravity. There have been several surges ofprogress in different directions in the past twentyyears， and this book tries to give the student ofthe field some ofthe salientideas.
　　It is not the purpose of this book to provide deep insights into the theory. I can only leave this to more competent colleagues. Its purpose is to provide the fastest possible introduction to the basic formalism and structure of string theory and its main properties and ramifications that are on a reasonably solid footing today.
　　This effort is unlike writing a textbook about the Standard Model of the fundamental interactions. It is less clear here what will turn out to be just mathematics， what will transform into real physics， and what will be neither ofthe above. However， the scope and deep interest of the endeavor， namely， to understand the basic mysteries of the universe at the most fundamental level， has driven more than a generation ofbright physicists and has provided breakthroughs in our theoretical understanding of both gravitational and gauge theories. It is this interest that drives researchers today， together with the hope that the theory will eventually be seriously confronted with experimental data.
　　There are several current and past areas of research in string theory .that have not been treated in this book. The reasons were varied. They include the subjects of the Feynman diagrams， it is obvious that there is essentially a universal three-point interaction in the theory. This interaction is dictated by the two-dimensional geometry of closed Riemann surfaces as is obvious from figure 1.2. The other related reason is the presence of an infinite tower of excitations with masses in multiples of the string scale. Their interactions are carefully tuned to become soft at distances larger than the string length ~s but still longer than the Planck length ~P.
　　For open strings the situation is subtler. There， UV divergences are present， but are interpreted as IR closed-string divergences in the dual dosed-string channel. This UV-IR open-dosed string duality is at the heart of many of the recent developments in the field.
　　Another key ingredient ofstring theoryis that it unifies gravity with gauge interactions. It does this in several different ways. The simplest is via the traditional KK approach. Super-string theory typically is defined in ten dimensions. Standard four-dimensional vacua can be obtained via compactification on a six-dimensional compact manifold. However， gauge symmetry can also arise from D-branes that sometimes are part of the vacuum （as in orientifolds）. There is even gauge symmetry coming from a nongeometrical part of the theory as happens in the heterotic string. The unified origin of gravity and gauge symmetry extends even further to other interactions. For example， the Yukawa interac-tions， crucial for giving mass to the SM particles， are also intimately related to the gauge interactions.
　　Unlike earlier Kaluza-Klein approaches to unification， string theory is capable of pro-viding， upon appropriate compactifications， chiral matter in four dimensions. This hap-pens via a subtle interplay between anomaly-related interactions and the process of compactification.
　　Another characteristic ingredient of string theory is that the presence of space-time fermions in the theory implies the appearance o

前言/序言

《弦理论导论》 本书旨在为对现代物理学前沿领域——弦理论——感兴趣的读者提供一个清晰、深入且全面的入门。弦理论作为一种试图统一描述所有基本粒子及其相互作用的理论框架，自问世以来便吸引了无数物理学家的目光，并催生了诸多革命性的思想。尽管其数学框架复杂且抽象，但理解其核心概念对于把握理论物理的未来发展方向至关重要。 本书将循序渐进地引导读者，从基础的物理概念出发，逐步构建对弦理论的认知。我们首先将回顾经典物理学和量子场论中的关键要素，例如洛伦兹变换、相对论性量子力学以及场论的基本思想，为理解弦理论的诞生背景和必要性打下坚实基础。接着，我们将介绍弦理论最核心的出发点：将基本粒子视为不是点状的，而是具有微小尺寸的、一维的“弦”。通过分析这些弦的振动模式，我们将看到如何自然地涌现出不同的粒子及其性质，例如质量和电荷。 本书的一个重要部分将聚焦于弦的动力学。我们将探讨弦在不同维度时空中的运动方程，以及它们如何通过相互碰撞和分裂来描述粒子之间的相互作用。这其中包括对玻色子弦理论的详细阐述，理解其产生的基本粒子以及紫外性质。随后，我们将引入超对称的概念，这是现代弦理论不可或缺的一部分。超对称将玻色子和费米子联系起来，解决了标准模型中的一些难题，并使得弦理论在数学上更加完备。我们将深入分析超弦理论的五种基本类型，以及它们之间通过对偶性所展现出的深刻联系，例如T对偶和S对偶。 理解弦理论的数学工具也是本书的重点。我们将介绍黎曼几何、微分几何以及拓扑学在描述弦的几何结构和动力学中所扮演的角色。例如，我们将探讨紧致化在高维时空中的重要性，以及如何在低维有效理论中观测到这些额外维度的影响。此外，我们还将触及共形场论（CFT）在弦理论中的核心地位，CFT是描述弦在共形不变时空中运动的强大工具，也是理解全息原理的关键。 本书还将对弦理论在解决现代物理学核心问题中的作用进行探讨。其中包括其在解释黑洞熵、量子引力以及可能统一标准模型粒子及其相互作用等方面的潜力。我们将讨论M理论的概念，它被认为是统一所有五种超弦理论的更深层次的理论框架。最后，本书将展望弦理论的未来发展方向，包括对不同模型的研究，以及其在宇宙学、粒子物理学以及数学等领域可能产生的深远影响。 本书的编写力求严谨而不失可读性，通过清晰的逻辑结构和丰富的例证，帮助读者克服弦理论的抽象性。我们相信，通过对本书内容的学习，读者将能够建立起对弦理论的坚实理解，并为进一步深入研究这一迷人的物理学领域做好准备。无论您是物理学专业的学生，还是对宇宙奥秘充满好奇的科学爱好者，本书都将是您探索弦理论世界的理想起点。