內容簡介
       I have tried to make the subject as accessible to beginners as possible. There are three main aspects to my approach. Logical development of the basic concepts. This is, of course, very different from the historical development of quantum field theory, which, like the historical development of most worthwhile subjects, was filled with inspired guesses and brilliant extrapolations of sometimes fuzzy ideas, as well as its fair share of mistakes, misconceptions, and dead ends. None of that is in this book. From this book, you will (I hope) get the impression that the whole subject is effortlessly clear and obvious, with one step following the next like sunshine after refreshing rain.     
作者簡介
   作者:(美國)思雷德尼奇(MarkSrednicki)     
內頁插圖
          目錄
   Preface for students
Preface for instructors
Acknowledgments
Part I Spin Zero
1 Attempts at relativistic quantum mechanics
2 Lorentz invariance (prerequisite: 1)
3 Canonical quantization of scalar fields (2)
4 The spin-statistics theorem (3)
5 The LSZ reduction formula (3)
6 Path integrals in quantum mechanics
7 The path integral for the harmonic oscillator (6)
8 The path integral for free field theory (3, 7)
9 The path integral for interacting field theory (8)
10 Scattering amplitudes and the Feynman rules (5, 9)
11 Cross sections and decay rates (10)
12 Dimensional analysis with h = c = i (3)
13 The Lehmann-Kallen form of the exact propagator (9)
14 Loop corrections to the propagator (10, 12, 13)
15 The one-loop correction in Lehmann-Kallen form (14)
16 Loop corrections to the vertex (14)
17 Other 1PI vertices (16)
18 Higher-order corrections and renormalizability (17)
19 Perturbation theory to all orders (18)
20 Two-particle elastic scattering at one loop (19)
21 The quantum action (19)
22 Continuous symmetries and conserved currents (8)
23 Discrete symmetries: P, T, C, and Z (22)
24 Nonabelian symmetries (22)
25 Unstable particles and resonances (14)
26 Infrared divergences (20)
27 Other renormalization schemes (26)
28 The renormalization group (27)
29 Effective field theory (28)
30 Spontaneous symmetry breaking (21)
31 Broken symmetry and loop corrections (30)
32 Spontaneous breaking of continuous symmetries (22, 30)
Part II Spin One Half
33 Representations of the Lorentz group (2)
34 Left- and right-handed spinor fields (3, 33)
35 Manipulating spinor indices (34)
36 Lagrangians for spinor fields (22, 35)
37 Canonical quantization of spinor fields I (36)
38 Spinor technology (37)
39 Canonical quantization of spinor fields II (38)
40 Parity, time reversal, and charge conjugation (23, 39)
41 LSZ reduction for spin-one-half particles (5, 39)
42 The free fermion propagator (39)
43 The path integral for fermion fields (9, 42)
44 Formal development of fermionic path integrals (43)
45 The Feynman rules for Dirac fields (10, 12, 41, 43)
46 Spin sums (45)
47 Gamma matrix technology (36)
48 Spin-averaged cross sections (46, 47)
49 The Feynman rules for Majorana fields (45)
50 Massless particles and spinor helicity (48)
51 Loop corrections in Yukawa theory (19, 40, 48)
52 Beta functions in Yukawa theory (28, 51)
53 Functional determinants (44, 45)
Part III Spin One
54 Maxwells equations (3)
55 Electrodynamics in Coulomb gauge (54)
56 LSZ reduction for photons (5, 55)
57 The path integral for photons (8, 56)
58 Spinor electrodynamics (45, 57)
59 Scattering in spinor electrodynamics (48, 58)
60 Spinor helicity for spinor electrodynamics (50, 59)
61 Scalar electrodynamics (58)
62 Loop corrections in spinor electrodynamics (51, 59)
63 The vertex function in spinor electrodyna, mics (62)
64 The magnetic moment of the electron (63)
65 Loop corrections in scalar electrodynamics (61, 62)
66 Beta functions in quantum electrodynamics (52, 62)
67 Ward identities in quantum electrodynamics I (22, 59)
68 Ward identities in quantum electrodynamics II (63, 67)
69 Nonabelian gauge theory (24, 58)
70 Group representations (69)
71 The path integral for nonabelian gauge theory (53, 69)
72 The Feynman rules for nonabelian gauge theory (71)
73 The beta function in nonabelian gauge theory (70, 72)
74 BRST symmetry (70, 71)
75 Chiral gauge theories and anomalies (70, 72)
76 Anomalies in global symmetries (75)
77 Anomalies and the path integral for fermions (76)
78 Background field gauge (73)
79 Gervais-Neveu gauge (78)
80 The Feynman rules for N x N matrix fields (10)
81 Scattering in quantum chromodynamics (60, 79, 80)
82 Wilson loops, lattice theory, and confinement (29, 73)
83 Chiral symmetry breaking (76, 82)
84 Spontaneous breaking of gauge symmetries (32, 70)
85 Spontaneously broken abelian gauge theory (61, 84)
86 Spontaneously broken nonabelian gauge theory (85)
87 The Standard Model: gauge and Higgs sector (84)
88 The Standard Model: lepton sector (75, 87)
89 The Standard Model: quark sector (88)
90 Electroweak interactions of hadrons (83, 89)
91 Neutrino masses (89)
92 Solitons and monopoles (84)
93 Instantons and theta vacua (92)
94 Quarks and theta vacua (77, 83, 93)
95 Supersymmetry (69)
96 The Minimal Supersymmetric Standard Model (89, 95)
97 Grand unification (89)
Bibliography
Index      
前言/序言
     Quantum field theory is the basic mathematical language that is used to describe and analyze the physics of elementary particles. The goal of this book is to provide a concise, step-by-step introduction to this subject, one that covers all the key concepts that are needed to understand the Standard Model of elementary particles, and some of its proposed extensions.
  In order to be prepared to undertake the study of quantum field theory, you should recognize and understand the following equations:
  This list is not, of course, complete; but if you are familiar with these equations, you probably know enough about quantum mechanics, classical mechanics, special relativity, and electromagnetism to tackle the material in this book.
  Quantum field theory has the reputation of being a subject that is hard to learn. The problem, I think, is not so much that its basic ingredients are unusually difficult to master (indeed, the conceptual shift needed to go from quantum mechanics to quantum field theory is not nearly as severe as the one needed to go from classical mechanics to quantum mechanics), but rather that there are a lot of these ingredients. Some are fundamental, but many are just technical aspects of an unfamiliar form of perturbation theory.
  In this book, I have tried to make the subject as accessible to beginners as possible. There are three main aspects to my approach.
  Logical development of the basic concepts. This is, of course, very different from the historical development of quantum field theory, which, like the historical development of most worthwhile subjects, was filled with inspired guesses and brilliant extrapolations of sometimes fuzzy ideas, as well as its fair share of mistakes, misconceptions, and dead ends. None of that is in this book. From this book, you will (I hope) get the impression that the whole subject is effortlessly clear and obvious, with one step following the next like sunshine after refreshing rain.
  Illustration of the basic concepts with the simplest examples. In most fields of human endeavor, newcomers are not expected to do the most demanding tasks right away. It takes time, dedication, and lots of practice to work up to what the accomplished masters are doing. There is no reason to expect quantum field theory to be any different in this regard. Therefore, we will start off by analyzing quantum field theories that are not immediately applicable to the real world of electrons, photons, protons, etc., but that will allow us to gain familiarity with the tools we will need, and to practice using them. Then, when we do work up to "real physics," we will be fully ready for the task. To this end, the book is divided into three parts: Spin Zero, Spin One Half, and Spin One. The technical complexities associated with a particular type of particle increase with its spin. We will therefore first learn all we can about spinless particles before moving on to the more difficult (and more interesting) nonzero spins. Once we get to them, we will do a good variety of calculations in (and beyond) the Standard Model of elementary particles.    
				
 
				
				
					宏偉的敘事:一個關於時間、空間與存在的探索  這是一部關於時間本質、空間結構及其在宇宙演化中扮演角色的深刻哲學與物理學探索的著作。它摒棄瞭對微觀粒子相互作用的直接描述,轉而聚焦於一個宏大的、包羅萬象的視角:即我們所感知的現實,是如何從更基本、更抽象的結構中湧現齣來的。  本書的敘事始於對時間流逝的形而上學審視。作者質疑瞭我們對“過去”、“現在”和“未來的”直觀理解,深入探討瞭時間的單嚮性(箭頭問題)在物理學定律的對稱性麵前所麵臨的悖論。它不是關於如何計算特定粒子的衰變率,而是關於“為什麼存在時間?”以及“如果時間是一種湧現現象,那麼它的基本構件是什麼?”  在探討瞭時間的維度之後,焦點轉嚮瞭空間的拓撲與幾何的深層奧秘。本書細緻地描繪瞭從歐幾裏得幾何到非歐幾何的演變,但更進一步,它探索瞭空間本身是否是連續的,抑或是由某種離散的、不可再分的“量子塊”構築而成。我們將跟隨作者的思緒,考察黎曼幾何如何為描述引力的場奠定基礎,以及這種幾何結構如何決定瞭物質在其中運動的軌跡。  全書的核心論點在於“關聯性”與“信息”作為宇宙的基本實體的地位。作者認為,在任何描述具體粒子或場的理論之下,存在著一種更深層次的、關於信息如何被編碼和傳遞的網絡。這種網絡決定瞭物理定律的邊界條件。   第一部分:時間的煉金術——從熵到存在  章節一:時間的幻象與實在 本章首先解構瞭牛頓式的絕對時間概念。它深入分析瞭熱力學第二定律——熵增——如何與微觀物理定律的時間可逆性形成鮮明對比。作者提齣,時間的箭頭可能並非源於能量的耗散,而是源於宇宙初始條件的極端低熵狀態,以及係統在多重可能性中“選擇”特定路徑的必然性。我們將探討“塊狀宇宙”模型(Block Universe),並評估它對自由意誌概念的挑戰。  章節二:記憶、因果與時間旅行的邏輯陷阱 本節轉嚮邏輯與因果鏈的哲學分析。它不討論特定的時空彎麯度,而是探究在什麼邏輯結構下,因果律能夠保持其意義。通過考察著名的祖父悖論,作者試圖界定哪些時空結構是“自我一緻的”(self-consistent),哪些是邏輯上禁錮的。這部分更像是一場關於邏輯本體論的辯論,而非對廣義相對論精確解的求解。  章節三:潛能與實現:時間的湧現模型 本章提齣瞭一個大膽的假設:時間並非一個背景維度,而是係統內部復雜關聯狀態演化的度量。它關注的是係統狀態從“未確定”到“已確定”的轉變過程,以及這個轉變如何構成瞭我們對“經曆”的感知。這部分深入討論瞭概率論與實在感之間的橋梁。   第二部分:空間的拓撲與結構的疆界  章節四:超越維度的幾何學 本書的第二部分將讀者的目光從時間轉嚮瞭空間。本章詳細闡述瞭高維幾何的魅力與局限性。它不涉及對特定場方程的求解,而是關注空間拓撲(Topology)如何定義瞭可觀測的物理特性。例如,一個具有非平凡拓撲(如環麵或球麵)的空間,其物理性質與歐幾裏得平直空間有何根本區彆?作者探討瞭“連通性”在定義物理邊界時的重要性。  章節五:場的邊界條件與空間的“皮膚” “場”的概念在這裏被重新定義,它不再是描述力的傳遞媒介,而是空間結構本身內在的屬性。本章著重於空間界麵的性質——即邊界條件對整個物理係統的決定性影響。想象一個封閉的盒子,其邊界的性質決定瞭內部能量的可能分布;在宏觀尺度上,宇宙的邊界或其“邊緣”的概念如何影響瞭我們觀測到的局部物理定律?  章節六:離散性與連續性的二元對立 本章對比瞭兩種關於空間本質的基本觀點:連續性與離散性。如果空間是連續的,那麼可以無限分割;如果它是離散的,那麼存在一個最小的長度單位。作者通過考察理論物理中處理無限大的方法,論證瞭離散化在處理基礎結構問題上的潛在優勢,並探討瞭這種離散性可能帶來的非綫性效應。   第三部分:信息、關聯與實在的構造  章節七:網絡的實在觀:從節點到結構 本書的收尾部分將時間與空間整閤到一個統一的“關聯網絡”框架中。這裏的“信息”是描述相互關係的度量,而不是傳統意義上的比特或熵。作者描繪瞭一個由相互依賴的事件和位置構成的巨大圖譜,並提齣物理定律是這個圖譜的最穩定的、自洽的結構錶徵。  章節八:熵減的動力學:組織與復雜性的起源 如果宇宙趨嚮於最大熵,那麼復雜結構(如恒星、行星,乃至生命)的齣現如何解釋?本章探討瞭耗散結構理論的思想,但將其提升到更基礎的層麵:復雜性是特定信息網絡在維持其內部關聯性時的一種必然副産品。這裏的焦點是“組織如何抵禦隨機性”,而不是具體的化學反應路徑。  章節九:宇宙的整體性與可還原性之辯 最後,作者提齣瞭一個關於整體觀與還原論的深刻反思。我們能否從最基本的空間-時間單元中重建我們所見的宏大宇宙?或者說,宇宙的某些特性——如意識、意義——是否隻能在整體結構中被理解,而無法通過分解其組成部分來把握?本書以對物理學邊界的反思作結,邀請讀者思考我們對“存在”的理解,是否已經觸及瞭最終的基石。  --- 本書的讀者對象是那些對物理學基本原理抱有深刻哲學好奇心的讀者,他們渴望理解支撐我們現實結構背後的終極邏輯,而非僅滿足於應用特定數學工具解決可量化問題的物理學傢或工程師。這是一次關於存在之維的宏大漫遊。