computo ergo sum

2026-10-09 · chapter Yang–Mills and the mass gapPart 11 Further considerations — beyond Assumption H, and other viewssymbols, where they are defined, units · Kiichi, Shiori and Rin

The whole book Contents and reading orders
  1. Part 0 Entrance — how to read this book
  2. 0-01 How to read this book
  3. 0-02 One picture
  4. 0-03 Reading the problem statement word by word
  5. 0-04 Four dimensions in mathematics and four dimensions in physics
  6. Part 1 Mathematical preparation
  7. 1-01 Vector spaces and linear maps
  8. 1-02 What a group is
  9. 1-03 Lie groups and Lie algebras
  10. 1-04 SU(2) and SU(3)
  11. 1-05 Manifolds and tangent spaces
  12. 1-06 Differential forms and the exterior derivative
  13. 1-07 Vector bundles and connections
  14. 1-08 Probability and measure
  15. 1-09 Probability in infinite dimensions
  16. 1-10 Hilbert spaces and self-adjoint operators
  17. 1-11 Fourier analysis and distributions
  18. 1-12 Detour: what happens only in four dimensions
  19. Part 2 Physical preparation
  20. 2-01 Lagrangians and the action
  21. 2-02 The idea of a field
  22. 2-03 Electromagnetism is a gauge theory
  23. 2-04 Special relativity and spacetime
  24. 2-05 The bones of quantum mechanics
  25. 2-06 The harmonic oscillator and creation and annihilation
  26. 2-07 The idea of the path integral
  27. 2-08 Statistical mechanics and phase transitions
  28. 2-09 Detour: the gap and the correlation length in the Ising model
  29. 2-10 The relaxation time and the dynamical exponent z
  30. Part 3 Yang–Mills theory (classical)
  31. 3-01 The gauge principle
  32. 3-02 Non-abelian gauge fields
  33. 3-03 The action and the equations
  34. 3-04 Gauge theory as geometry
  35. 3-05 Instantons and topology
  36. 3-06 Detour: Donaldson and exotic R⁴
  37. 3-07 Yang–Mills inside the Standard Model
  38. Part 4 Quantisation
  39. 4-01 Canonical quantisation and the Hamiltonian
  40. 4-02 The path integral and Euclideanisation
  41. 4-03 Perturbation theory and Feynman diagrams
  42. 4-04 Divergences and renormalisation
  43. 4-05 The algebra of divergences
  44. 4-06 Asymptotic freedom
  45. 4-07 Dimensional transmutation and Λ
  46. 4-08 Gauge fixing and Faddeev–Popov
  47. 4-09 The axioms of quantum field theory
  48. 4-10 The Osterwalder–Schrader axioms and reconstruction
  49. 4-11 The definition of the mass gap
  50. 4-12 Detour: the perturbation series diverges
  51. Part 5 Lattice gauge theory
  52. 5-01 Wilson's lattice
  53. 5-02 The strong-coupling expansion
  54. 5-03 Reflection positivity and the transfer matrix
  55. 5-04 The infinite-volume limit and the cluster expansion
  56. 5-05 Weak coupling and the continuum limit
  57. 5-06 How U(1) differs from the non-abelian case
  58. 5-07 The Monte Carlo method
  59. 5-08 Measuring glueballs and the string tension
  60. 5-09 What to hold fixed when taking the limit
  61. 5-10 Lattice gauge theory with finite groups
  62. 5-11 Detour: Bakry–Émery and one-link integration
  63. Part 6 Constructive field theory
  64. 6-01 What constructive field theory is
  65. 6-02 Solvability in two dimensions and the Yang–Mills measure
  66. 6-03 Constructing scalar fields
  67. 6-04 The cluster expansion
  68. 6-05 The sequence of renormalisation group steps
  69. 6-06 Ultraviolet stability of three-dimensional Yang–Mills
  70. 6-07 Four dimensions
  71. 6-08 Triviality of φ⁴ in four dimensions
  72. 6-09 Stochastic quantisation and regularity structures
  73. 6-10 Where four dimensions stops
  74. 6-11 Obstacles other than divergence
  75. 6-12 Detour: "if 1/0 is given a symbol"
  76. Part 7 From the side of physics
  77. 7-01 How physics sees it
  78. 7-02 Mechanisms of confinement
  79. 7-03 The string picture
  80. 7-04 Large N
  81. 7-05 String theory and extra dimensions
  82. 7-06 How extra dimensions become invisible
  83. 7-07 Where gauge fields come from
  84. 7-08 Holography
  85. 7-09 The mass gap becomes geometry
  86. 7-10 Back to four dimensions
  87. 7-11 Supersymmetry and Seiberg–Witten
  88. 7-12 The sentence that plays the role of an equivalence principle
  89. 7-13 Where the way physics digs parts from mathematics
  90. Part 8 A dictionary of two languages — the physical and the mathematical view
  91. 8-01 How to read the dictionary
  92. 8-02 Dictionary A
  93. 8-03 Dictionary B
  94. 8-04 Dictionary C
  95. 8-05 The physical counterparts of our assumptions
  96. Part 9 Where things stand, and open tasks
  97. 9-01 How far the world has come
  98. 9-02 Where the two ways of digging part
  99. 9-03 Candidates for new concepts
  100. 9-04 The list of open tasks
  101. 9-05 Common misconceptions
  102. Part 10 Towards a proof of the mass gap — building the first step of the staircase
  103. 10-00 Entrance — the staircase, and the random walk, the ruler and the clock
  104. 10-01 The line of construction and Assumption H
  105. 10-02 Roads tried on the four-dimensional lattice, and walls
  106. 10-03 The four steps of the staircase — why we start from 0+1 dimensions
  107. 10-04 The path measure of the double well, and kinks
  108. 10-05 The statement of the first step — four conditions and Proposition 4.5
  109. 10-06 (H1) Local Poincaré within a phase
  110. 10-07 The map of (H2) — seven routes and the seam of the ring
  111. 10-08 What computer-assisted means — the conditions on the chain inside the window
  112. 10-09 The sector framework and the three strands of route 5
  113. 10-10 The list of detour plans — types of breakage
  114. 10-11 (H3)(H4) and the constant of the core
  115. 10-12 The integrated table and the dependency graph
  116. 10-13 Lean statements and the limits of machine checking
  117. 10-14 Reconciliation — the numbers of the record and the known numbers
  118. 10-15 What remains and its cost — the distance to a theorem
  119. 10-16 What is not claimed
  120. 10-17 Insights and small questions
  121. Part 11 Further considerations — beyond Assumption H, and other views
  122. 11-00 Further considerations — entrance
  123. 11-01 One form that obstructs H — a nearly conserved global quantity
  124. 11-02 Choosing the ruler and the coordinates again — the length at which conservation breaks
  125. 11-03 Two ways to repair H — the sector H and the local H
  126. 11-04 Which H the one-sided bridge needs
  127. 11-05 Making time continuous — the Hamiltonian lattice and the vacuum measure
  128. 11-06 Paying with rarity instead of convexity — renormalisation on groups and log-Sobolev
  129. 11-07 Because it is four dimensions — the dimensionless coupling and topology
  130. 11-08 Questions, and what is not claimed
  131. 11-A1 Table of notation for Part 11
  132. Appendices
  133. A-01 Table of notation
  134. A-02 Glossary
  135. A-03 Guide to the literature
  136. A-04 Lean and machine checking
  137. A-05 How this book was made
  138. A-06 Index of assumptions

Table of notation for Part 11

What this page shows — A list of the symbols used in Part 11. For each symbol, its meaning, where it is defined, its unit, and whether it is the same quantity as the symbol with the same letter in Part 10 or a different one.

Prerequisite chapters — None. The notation of Part 10 is in 10-01 §01 and A-01 Table of notation.

Said first — Quantities are counted in lattice units (the lattice spacing is 1). Langevin time has the dimension of length squared (diffusion), and the value of CPC_P measured in physical units is a2CPa^2C_P. Numbers are values under the conditions of the chapter of definition, and their labels are in that chapter.

01

List of symbols

Table 1 Symbols of Part 11 ("Same" = the same quantity as the same letter in Part 10; "New" = a symbol added in Part 11)
SymbolMeaningWhere definedUnit (lattice) / physical readingCorrespondence with Part 10
ℓ\ellA ruler of length given from outside (independent of the gap). In four dimensions ξRG\xi_{\rm RG}; for the 0+1 double well 1/ωb=11/\omega_b=111-03 §02Length / aℓa\ellNew (in four dimensions the same quantity as ξRG\xi_{\rm RG} of 10-01 §07)
ξ\xiCorrelation length 1/mlat1/m_{\rm lat}. In 0+1, ℏ/Δ\hbar/\Delta(1) and (17) of 10-01Length / aξa\xiSame
ξRG\xi_{\rm RG}The bookkeeping length (the length fixed by counting the steps that coarsen the lattice) =1/a=1/a10-01 §07Length / 1Same
ξXY\xi_{XY}The static length of the two-dimensional U(1)U(1) strip, −1/ln⁡(I1(β)/I0(β))-1/\ln(I_1(\beta)/I_0(\beta)) (the inverse of the string tension)11-01 §02, 11-02LengthNew
R=cℓR=c\ellSide of the local window or box11-03 §03LengthNew
ccThe ratio of the window length to the ruler(2) of 11-03DimensionlessNew
D\mathcal DThe algebra of time-averaged functionals (weights with bounded support)(1) of 11-03—New (fixes the collection over which the supremum in (7) of 10-01 is taken)
Dc\mathcal D_cThe subfamily of D\mathcal D whose weights have support in the window [0,cℓ][0,c\ell](2) of 11-03—New
F1\mathcal F_1The family of time-integrated single-time functions11-04—A name given to the family of test functions of Proposition B of 10-01
CPC_PThe Poincaré constant sup⁡Var⁡/E\sup\operatorname{Var}/\mathcal E (path measure)(7) of 10-01. In Part 11 the supremum is taken over D\mathcal DLength squared (Langevin time) / a2CPa^2C_PSame ((β) of 10-01 Table 3)
CPloc(c)C_P^{\rm loc}(c)The local Poincaré constant (the supremum over Dc\mathcal D_c)(2) of 11-03Length squaredNew
CPloc,0(R)C_P^{\rm loc,0}(R)The value of the massless reference in the same box with the same graduation, =Γ(R)R2=\Gamma(R)R^2(4)(5) of 11-03Length squaredNew
K(c)K(c)The constant of the local H↑ in absolute form, CPloc(c)≤K(c)ℓ2C_P^{\rm loc}(c)\le K(c)\ell^2(3) of 11-03DimensionlessThe local version of CC in (14) of 10-01 (KK in Lean)
KrelK_{\rm rel}The ratio CPloc/CPloc,0C_P^{\rm loc}/C_P^{\rm loc,0}(5) of 11-03DimensionlessNew
Γ\GammaThe coefficient of the value for the reference box, CPloc,0(R)/R2C_P^{\rm loc,0}(R)/R^2. Γ∞=0.0740\Gamma_\infty=0.0740 for the scalar, ΓQ=0.0277\Gamma_Q=0.0277 for the gauge quotient11-03 §03, Table 1DimensionlessNew
λW\lambda_WThe Dirichlet value of the box within the test space multiplied by R2R^2 (4π24\pi^2 for the scalar, 72.072.0 for the gauge quotient). For a window function WW, ∥∇W∥2/∥W∥2\|\nabla W\|^2/\|W\|^2(7) of 11-01, 11-03 Table 1DimensionlessNew
κ\kappaThe constant comparing the Langevin metric with the metric of the kinetic term ((A3)). A different quantity from the correction κ to the raw rate on the strip in 11-02 §05 (which is neither κ_BE nor this κ)Proposition B of 10-01DimensionlessSame
κBE\kappa_{\rm BE}The lower bound on the Bakry–Émery curvature. A different quantity from the comparison constant κ of Proposition B11-06 §01Inverse length squaredNew
ssThe rate of rarity (the exponent with which the weight of defects falls as e^(−s/ħ)). The same quantity as ℓ of Part 1011-06 §03Dimensionless (in units of action)The rarity exponent ℓ of 10-09
K∗K_*The threshold of the bridge κ/(λWΓ)\kappa/(\lambda_W\Gamma)11-04DimensionlessNew
ℓc\ell_cThe length at which conservation breaks on the two-dimensional U(1)U(1) strip (the bend in the relaxation of the flux dipole)11-01 §02, 11-02LengthNew
ℓ∗\ell_*The length at which conservation breaks (the general name. The candidate definition is (2) of 11-02: the smallest R at which the ratio reaches half its saturation value)11-02LengthNew
R∗R_*The crossing length dλW/h\sqrt{d\lambda_W/h} (the boundary between the regimes of transport and of the barrier)(7) of 11-01LengthNew
λQ\lambda_QThe relaxation rate of the topological charge of the strip, 1/τint(Q)1/\tau_{\rm int}(Q)11-02Inverse Langevin timeNew
τint\tau_{\rm int}Integrated autocorrelation time(1) of 11-01, 10-02 §05Langevin time (in the originals, numbers of sweeps or molecular-dynamics time)Same
mmThe gap as an inverse time, m=Δ/ℏm=\Delta/\hbar. In four dimensions mlatm_{\rm lat}(1) and (17) of 10-01Inverse lengthSame (mlatm_{\rm lat})
mphysm_{\rm phys}The mass in physical units mℓm\ell (mlatξRGm_{\rm lat}\xi_{\rm RG} in four dimensions)(12)(16) of 10-01Dimensionless (physical units)Same
Δ\DeltaThe gap of the Hamiltonian E1−E0E_1-E_0Proposition B of 10-01EnergyRestricted to one meaning (§02 below)
ωb\omega_bThe angular frequency at the bottom of the double well V′′(±1)=1\sqrt{V''(\pm1)}=1(7) of 11-03, 11-04Inverse timeNew (a quantity of the model of 10-04)
S0S_0The kink action 2/32/310-04 §03ActionSame
φ(x)\varphi(x)The window factor 1−(1−e−x)/x1-(1-e^{-x})/xThe bracket in (17) of 10-01, 11-04DimensionlessSame (different from the plaquette angle φp\varphi_p)
φp\varphi_pThe plaquette angle of the two-dimensional strip11-01 §02, 11-02AngleNew
Q, QsQ,\ Q_sThe topological charge, the smoothed topological charge. On the two-dimensional strip Q=∑p[φp]/2πQ=\sum_p[\varphi_p]/2\pi11-01 §02, 11-03 §04Integer (QsQ_s is real)The same as QQ in the note of 10-01 §05
χt, h, d, g\chi_t,\ h,\ d,\ gThe topological susceptibility, the density of breaking of conservation, the transport coefficient, the coefficient of the boundary layer(4)(5) of 11-01Lattice units (h,d,gh,d,g depend on the graduation of E\mathcal E)New
CPsec(n), CtransC_P^{\rm sec}(n),\ C_{\rm trans}The Poincaré constant of a sector, the quantity between sectors(8)(10) of 11-03Length squaredNew
02

Symbols with the same letter but different meanings

Δ\Delta. In 10-01 of Part 10, Δ\Delta was used in two meanings: Δ(β)=mlat/a\Delta(\beta)=m_{\rm lat}/a of (1) (the mass in physical units) and Δ=E1−E0\Delta=E_1-E_0 of Proposition B (the gap of the Hamiltonian). In Part 11, Δ\Delta is restricted to the meaning E1−E0E_1-E_0 of Proposition B, and the mass in physical units is written mphysm_{\rm phys}.

KK. (14) of 10-01 writes the constant of H↑ as CC, and the Lean theorems write the same constant as KK. K(c)K(c) in Part 11 is its local version, KrelK_{\rm rel} is the constant of the ratio form, and K∗K_* is the threshold of the bridge. The three are different quantities.

φ\varphi. The window factor φ(x)\varphi(x) carries an argument, and the plaquette angle of the two-dimensional strip is φp\varphi_p with a subscript.

QQ. The four-dimensional topological charge and the topological charge of the two-dimensional strip are written with the same letter. Both are "global integers not reflected in the gap", examples of QQ of the pattern of 11-01. The two-dimensional numbers do not imply anything for four dimensions.

Symbols carrying λ\lambda. λ1\lambda_1 (the Langevin gap =1/CP=1/C_P, 10-01), λW\lambda_W (the Dirichlet value of the box) and λQ\lambda_Q (the relaxation rate of the topological charge of the strip) are different quantities.

← 11-08 Questions, and what is not claimedContentsA-01 Table of notation →

Revised 2026-10-09: first version.
2026-10-09: added to Table 1 where the candidate definition of ℓ_* is, the two meanings of κ, κ_BE, and the rate of rarity s.