The whole book Contents and reading orders
- Part 0 Entrance — how to read this book
- 0-01 How to read this book
- 0-02 One picture
- 0-03 Reading the problem statement word by word
- 0-04 Four dimensions in mathematics and four dimensions in physics
- Part 1 Mathematical preparation
- 1-01 Vector spaces and linear maps
- 1-02 What a group is
- 1-03 Lie groups and Lie algebras
- 1-04 SU(2) and SU(3)
- 1-05 Manifolds and tangent spaces
- 1-06 Differential forms and the exterior derivative
- 1-07 Vector bundles and connections
- 1-08 Probability and measure
- 1-09 Probability in infinite dimensions
- 1-10 Hilbert spaces and self-adjoint operators
- 1-11 Fourier analysis and distributions
- 1-12 Detour: what happens only in four dimensions
- Part 2 Physical preparation
- 2-01 Lagrangians and the action
- 2-02 The idea of a field
- 2-03 Electromagnetism is a gauge theory
- 2-04 Special relativity and spacetime
- 2-05 The bones of quantum mechanics
- 2-06 The harmonic oscillator and creation and annihilation
- 2-07 The idea of the path integral
- 2-08 Statistical mechanics and phase transitions
- 2-09 Detour: the gap and the correlation length in the Ising model
- 2-10 The relaxation time and the dynamical exponent z
- Part 3 Yang–Mills theory (classical)
- 3-01 The gauge principle
- 3-02 Non-abelian gauge fields
- 3-03 The action and the equations
- 3-04 Gauge theory as geometry
- 3-05 Instantons and topology
- 3-06 Detour: Donaldson and exotic R⁴
- 3-07 Yang–Mills inside the Standard Model
- Part 4 Quantisation
- 4-01 Canonical quantisation and the Hamiltonian
- 4-02 The path integral and Euclideanisation
- 4-03 Perturbation theory and Feynman diagrams
- 4-04 Divergences and renormalisation
- 4-05 The algebra of divergences
- 4-06 Asymptotic freedom
- 4-07 Dimensional transmutation and Λ
- 4-08 Gauge fixing and Faddeev–Popov
- 4-09 The axioms of quantum field theory
- 4-10 The Osterwalder–Schrader axioms and reconstruction
- 4-11 The definition of the mass gap
- 4-12 Detour: the perturbation series diverges
- Part 5 Lattice gauge theory
- 5-01 Wilson's lattice
- 5-02 The strong-coupling expansion
- 5-03 Reflection positivity and the transfer matrix
- 5-04 The infinite-volume limit and the cluster expansion
- 5-05 Weak coupling and the continuum limit
- 5-06 How U(1) differs from the non-abelian case
- 5-07 The Monte Carlo method
- 5-08 Measuring glueballs and the string tension
- 5-09 What to hold fixed when taking the limit
- 5-10 Lattice gauge theory with finite groups
- 5-11 Detour: Bakry–Émery and one-link integration
- Part 6 Constructive field theory
- 6-01 What constructive field theory is
- 6-02 Solvability in two dimensions and the Yang–Mills measure
- 6-03 Constructing scalar fields
- 6-04 The cluster expansion
- 6-05 The sequence of renormalisation group steps
- 6-06 Ultraviolet stability of three-dimensional Yang–Mills
- 6-07 Four dimensions
- 6-08 Triviality of φ⁴ in four dimensions
- 6-09 Stochastic quantisation and regularity structures
- 6-10 Where four dimensions stops
- 6-11 Obstacles other than divergence
- 6-12 Detour: "if 1/0 is given a symbol"
- Part 7 From the side of physics
- 7-01 How physics sees it
- 7-02 Mechanisms of confinement
- 7-03 The string picture
- 7-04 Large N
- 7-05 String theory and extra dimensions
- 7-06 How extra dimensions become invisible
- 7-07 Where gauge fields come from
- 7-08 Holography
- 7-09 The mass gap becomes geometry
- 7-10 Back to four dimensions
- 7-11 Supersymmetry and Seiberg–Witten
- 7-12 The sentence that plays the role of an equivalence principle
- 7-13 Where the way physics digs parts from mathematics
- Part 8 A dictionary of two languages — the physical and the mathematical view
- 8-01 How to read the dictionary
- 8-02 Dictionary A
- 8-03 Dictionary B
- 8-04 Dictionary C
- 8-05 The physical counterparts of our assumptions
- Part 9 Where things stand, and open tasks
- 9-01 How far the world has come
- 9-02 Where the two ways of digging part
- 9-03 Candidates for new concepts
- 9-04 The list of open tasks
- 9-05 Common misconceptions
- Part 10 Towards a proof of the mass gap — building the first step of the staircase
- 10-00 Entrance — the staircase, and the random walk, the ruler and the clock
- 10-01 The line of construction and Assumption H
- 10-02 Roads tried on the four-dimensional lattice, and walls
- 10-03 The four steps of the staircase — why we start from 0+1 dimensions
- 10-04 The path measure of the double well, and kinks
- 10-05 The statement of the first step — four conditions and Proposition 4.5
- 10-06 (H1) Local Poincaré within a phase
- 10-07 The map of (H2) — seven routes and the seam of the ring
- 10-08 What computer-assisted means — the conditions on the chain inside the window
- 10-09 The sector framework and the three strands of route 5
- 10-10 The list of detour plans — types of breakage
- 10-11 (H3)(H4) and the constant of the core
- 10-12 The integrated table and the dependency graph
- 10-13 Lean statements and the limits of machine checking
- 10-14 Reconciliation — the numbers of the record and the known numbers
- 10-15 What remains and its cost — the distance to a theorem
- 10-16 What is not claimed
- 10-17 Insights and small questions
- Part 11 Further considerations — beyond Assumption H, and other views
- 11-00 Further considerations — entrance
- 11-01 One form that obstructs H — a nearly conserved global quantity
- 11-02 Choosing the ruler and the coordinates again — the length at which conservation breaks
- 11-03 Two ways to repair H — the sector H and the local H
- 11-04 Which H the one-sided bridge needs
- 11-05 Making time continuous — the Hamiltonian lattice and the vacuum measure
- 11-06 Paying with rarity instead of convexity — renormalisation on groups and log-Sobolev
- 11-07 Because it is four dimensions — the dimensionless coupling and topology
- 11-08 Questions, and what is not claimed
- 11-A1 Table of notation for Part 11
- Appendices
- A-01 Table of notation
- A-02 Glossary
- A-03 Guide to the literature
- A-04 Lean and machine checking
- A-05 How this book was made
- A-06 Index of assumptions
The statement of the first step — four conditions and Proposition 4.5
What this chapter shows — We split the upper side for the path measure of the double well into four conditions (H1)–(H4). Condition (H3) reduces infinitely long paths to boxes of length , condition (H4) controls the gap inside a box, and conditions (H1)(H2) enter (H4) as the fast part inside the box. On top of this we state, as one line of argument, how is squeezed into and the power form of H follows, adding for each step "what it uses and which grade it has". At the end of the chapter the steps of Proposition 4.5 are collected in a table of the five grades and a dependency graph.
Prerequisite chapters — 10-03 §05 (the power form of H and the shape of Proposition 4.5), 10-04 (the path measure, kinks, Proposition L), 1-10 §07–§09 (Poincaré inequalities), 10-00 §01 (the labels of the five grades).
Said first — The level is [Y3]. Proposition 4.5 is algebra on top of four conditions, and every one of the four conditions leaves assumption rows. This chapter does not say that the first step is closed. It names what would have to be shown to close it. This part is a study that chose Assumption H as its foothold, and the split into four conditions is one way of building within it. Other views are treated in Part 11.
- The splitting of the variance — the algebra of splitting into two valleys, and why that alone is not enough for long paths
- The parts shown — the algebra of the splitting, the convex core, the reduced plateau, the diffusion coefficient of kinks
- The statements of the four conditions — for which measure, which constant, uniform in what
- Proposition 4.5 as one line — reduction to the box → inside the box → → → the power form of H
- The distance from known theorems — where they reach and where they do not (Table 1)
- The table of the five grades — the rows of the steps of Proposition 4.5 (Table 2)
- The dependency graph — checking by the numbers that there is no circle
- A that fits all, and where the four conditions stand — a guide to 10-06–10-12
The splitting of the variance — the algebra of splitting into two valleys
The setting is as in 10-04 §01. The lattice is , the action , the measure , the Dirichlet form , , the diffusion coefficient of kinks , and . We take first and then .
The first tool for building the upper side is the algebra of splitting the measure into two parts. Split the space of configurations in two (for example by the sign of the smoothed value of the path) and write (, , and the measures restricted to each part and normalised). Then for every
holds Proved here (the identity for the variance of a mixture. Put and , split on each part into and , and use ).
Suppose that each of the three terms on the right-hand side has the following inequality.
The first is local Poincaré inside a valley, the second is the "transport of the mean difference", which controls the difference of the means of the two valleys by the Dirichlet form, and the third is the additivity of the form. Since ,
holds Proved here Leansplit_poincare_le (assumptions: , , the splitting formula (1), the two local Poincaré inequalities, the mean difference, additivity of the form, non-negative constants). The splitting formula (1) has the same form as Lemma 2.4 of Menz–Schlichting Cited (the skeleton of the Poincaré version of finite-dimensional Eyring–Kramers).
Of the two constants in (3), later becomes condition (H1) and becomes condition (H2). But (3) cannot be applied to long paths as it stands.
For long paths, one coarse variable is not enough. (1) is a split of the form "take one slow variable (which valley the path is in) and treat the rest as fast". When the path is much longer than the correlation length (), long-wave fluctuations of the density of kinks form a continuous band, and the Poincaré constant of the conditional measure with one valley fixed stays of the same size as (the Glauber band of 10-04 §05). That is, does not become . So instead of taking a number of slow variables proportional to the volume, we cut the problem into boxes of length . This is condition (H3) (reduction to the box) and (H4) (the gap inside the box), and (H1)(H2) are used inside the box (§04).
The parts shown — the algebra of the splitting, the convex core, the reduced plateau, the diffusion coefficient
First we list the parts of the construction of the upper side that can be said without assumption rows.
(a) The algebra of the splitting. (1)–(3) are as in §01 Proved here.
(b) The convex core. For the measure restricted to the convex region deep in a valley, (), the Hessian of the action is at least (), so Bakry–Émery on a convex region gives uniformly in the length, and the boundary Proved here (the lower bound on the curvature) Cited (Bakry–Émery on a convex region, Theorem 1.2 of Kolesnikov–Milman). The proof and the Lean statement are in 10-04 §06. But excursions out of the core have smaller action than a kink, and exponentially many of them fit in an interval of length , so the convex core alone does not give (H1).
(c) The two-state value of the reduced plateau. On a short ring () the path that moves between valleys is one pair of kinks, and the separation of the pair becomes the one slow coordinate. In the one-dimensional model that keeps only ( moves with diffusion coefficient , with an atom of a valley at each end and the plateau weight in between), we control the mean difference by the Cauchy–Schwarz inequality, write the difference of the values at the two ends of as , and
gives a value of the form , with equality nearly attained by the sign test function Proved here ((4) is the Cauchy–Schwarz inequality) Leanreduced_two_state_value (assumptions: , , , with the integral of the plateau weight). The reduced model itself (that everything other than may be thrown away) is an assumption of the model, and this value is "a value on the reduced model" Assumption.
(d) The diffusion coefficient of kinks. The position of a single kink moves with diffusion coefficient . At the level of the process of a single interface, this is a copy of the coefficient of a known theorem Cited ((9) of 10-04 §03). It is not a statement about the gap of the whole path.
These four are all. The remaining parts, namely that local Poincaré inside a valley is uniform in the length and in , that transport along the family of flat saddles is uniform in the dimension, the reduction of long paths to boxes, and the gap inside a box, lie outside the assumptions of known theorems (§05). We name them as four conditions.
The statements of the four conditions — for which measure, which constant, uniform in what
We write the four conditions making three things explicit: the measure, the constant and the uniformity. All are statements about the 0+1-dimensional double well , the lattice and the Dirichlet form . "Uniform" means that for some with , the constant does not depend on (does not grow as ).
Measure: the measure of the phase without kinks. The measure restricted to configurations in which the path stays on the side of one valley, for example to configurations with at every site (reflected at the wall ). Constant: the Poincaré constant of , that is, . Uniformity: uniformly in and in the length of the path. For use inside the box, the version (H1seg) for scraps with end values (length ) is needed, and it must also be uniform in the end values.
Measure: the conditional measure of configurations in the tube around the family of kink–antikink pairs (the family of saddles, parametrised by the centre and separation of the pair, along which the action is almost flat). Constant: the constant of transport of the mean difference along that family from valley to valley (of the type of in (2)), and the Poincaré constant inside the tube. Uniformity: uniform in the number of sites of the path (the dimension) and in . For use inside the box it becomes two rows: Poincaré in the tube uniform in tube length (H2tube), and Poincaré of the core inside the tube (the interval that stays near the top) uniform in the core length (T0′P).
Measure: the measure on the lattice line with , and the conditional measure with the values on both neighbours of a box of length sites () fixed. Constants: and the constant of mixing between boxes. Statement: . Uniformity: depends only on lengths in units of ( and the fraction of overlap of the boxes), not on or the boundary values.
Measure: the conditional measure of a box of length . The number of kinks in the box is on average (the density of kinks is , so the expectation is ). Constant: the gap . Statement: , that is, (). Uniformity: is uniform in and in all boundary values (it may depend on ).
The four are not conditions of the same weight. (H3) is the step that "moves the problem of long paths to a problem of boxes", (H4) is the step that "splits the inside of a box into slow variables (the arrangement of kinks) and fast variables", and (H1)(H2) are statements on the side of those fast variables. The next section puts into one line the place where (H1)(H2) enter (H4).
To be precise, the conditions named (H1)–(H4) are different from Assumption H (the power statement, 10-01 §05). Assumption H is a statement on the side of the conclusion, and (H1)–(H4) are conditions put in place to derive it in the first step (10-03 §05).
Proposition 4.5 as one line
For the path measure of the 0+1-dimensional double well (lattice , taking first), assume conditions (H1)–(H4) and the premise rows of Step 0 below. Then as
holds, hence , and the power form of H, , follows.
(5) is the same formula as (15) of 10-04 §05 and (3) of 10-03 §05. Below, each step is given with "what it uses" and its grade.
Step 0 The premise rows
That the measure with is uniquely determined (simplicity of the principal eigenvalue, from the positivity of the integral kernel of the transfer operator) Assumption (the original source for the version with a positive kernel on has not been checked; the same row as in 10-04 §01). The relation between of the finite ring and of the measure with (the step of the limit), and the regularity of the functions used in the steps below (conditional measures, smoothness of the kink coordinates) Assumption. These three are premises placed outside Proposition 4.5, and they are counted as assumption rows in the integrated table (10-12) too.
Step 1 Reduction to the box — condition (H3) in the form of Proposition H3
Cover the line by boxes of length sites. Neighbouring boxes overlap in sites (), and the boxes are divided alternately into an even family and an odd family . Let be the -algebra generated by the values at the sites outside the even family, define in the same way, and let the maximal correlation of the two -algebras be
.
Lemma TP (two projections). If , then for all , .
Proved here Proof. Put and . Then , while . Hence , and adding gives at least . ∎ Leantwo_proj_var (assumption: . The geometry of the projections is outside Lean).
The product over boxes. Even boxes are sites apart, so by the Markov property of the nearest-neighbour interaction they are mutually independent under . The variance of a function of independent components is at most the sum of the conditional variances component by component (of the Efron–Stein type), so
holds Proved here (the Markov property and the variance inequality for independent products; the proof is placed in 10-11). The same holds for the odd family. Each site lies in the even family at most once and in the odd family at most once, and only the overlaps lie in both.
Averaging over shifts. Shift the arrangement of boxes by at a time, in ways. Every shift has the same , and the overlap sites are disjoint between shifts. Applying Lemma TP and (7) to each shift and averaging gives
Proved here Leanbox_two_family, box_shift_average (assumptions: the two-family inequality for each shift, , the sum of the forms on the overlaps at most ). This is Proposition H3, and of (H3) corresponds to . This step uses only Poincaré inequalities, not the logarithmic Sobolev inequality.
One assumption row remains in (8): that the alternating maximal correlation is uniform in (row (MIXalt)). Its value is read as at and overlap Reading (a family value copied from the closed formula for the two-state telegraph chain; not a proof of an upper bound). The type of the reduction to the box has the same form as the box dynamics for Glauber dynamics of discrete spins (Propositions 3.4 and 3.5 of Martinelli's lectures) Cited (discrete spins, in the form of a total-variation coupling; here rewritten in one dimension, in , in the form of maximal correlation).
Step 2 Inside the box — condition (H4) in the form of Proposition H4, and where (H1)(H2) enter
Fix a box () and boundary values . Let the slow variable inside the box be = the arrangement of kinks (the number of kinks, and the position of each kink defined by projection onto the manifold of kinks). Splitting the variance by gives
Proved here (the identity for conditional expectations).
First term = the fast side. (H1) and (H2) enter here. By the nearest-neighbour Markov property, the conditional measure with fixed splits into a product of the following parts. (i) Scraps of the phase without kinks between kinks (length , with values at both ends). (ii) The tube around each kink or kink pair, and the core inside it (the interval that stays near the top). The Poincaré constant of a product measure is the maximum of the constants of the components (the variance inequality for independent products), so
Proved here (the Poincaré constant of a product measure is the maximum of the constants of the components. That it splits into a product depends on how is defined, and its regularity is included in the row of Step 0). The constant of (i) is the scrap version of condition (H1), and the constants of (ii) are the tube and core rows of condition (H2) Assumption (all three are assumption rows).
Second term = the slow side. Longitudinal transport along the family of saddles enters here. is a function of alone, and its fluctuations relax by the diffusion of kink positions and by the creation and annihilation of kink pairs. The Dirichlet form on has mobility per kink of the form (row (Mob): the projection formula, 10-04 §03). Here we put two rows.
- Row (KG): the Poincaré constant of the box for the reduced kink gas, , with uniform in and the boundary values Assumption (the assumption that the kink gas falls into the same type as the Glauber dynamics of the one-dimensional Ising model).
- Row (X): the cross term , with uniform in and the boundary values Assumption (of the type of the cross constant of a two-scale inequality; a statement of this form is not taken from a known theorem).
of (KG) comes from reading in the continuum limit the closed formula for the gap of the Glauber box with fixed ends, ,
which gives Proved here (the algebra of (11)) Leankg_constant (assumption: ). The first term is the creation and annihilation of pairs, and the second is the diffusion of kink positions. When a boundary value is near the top, half a kink can sit at the end of the box (corresponding to a free end), and in the including that case , read as at Reading (a family value obtained from lattice values of the gap of the free-end box of the one-dimensional Ising model).
Combining (9)(10) with (KG)(X) gives
Proved here LeanH4_two_scale (assumptions: the inequality of decomposition (9), first term , (KG) , (X), ), H4_gap_form (assumptions: , , , , , the two inequalities above). This is Proposition H4.
The second term of is multiplied by , and is of size at the three values of () Reading (Table 2 of 10-04 §07). Unless grows exponentially in , this term vanishes as . In this sense the demand of (H1) for is a demand with room to spare.
A note on where (H2) goes. In the two-valley split of §01, (H2) was the mean-difference constant itself. In the box split, the direction along the family of saddles (the kink positions) was taken as the slow variable , so transport in that direction is handled by (KG) and (X) of the second term, and what remains in (H2) is the Poincaré of the tube and the core with fixed. In this book the tube and core rows are counted as rows of (H2), and (KG)(X) as rows of (H4) (the same counting as the integrated table, 10-12).
Step 3 Composition —
Putting (12) into of (8) and using and gives
Proved here LeanH3_H4_compose (assumptions: the conclusion (8) of Proposition H3, the conclusion of Proposition H4, , , , , ). That does not depend on is the uniformity of , , , and , that is, the very content of the assumption rows.
Putting in the values of the reduced model (, , ) gives at (the including boundary values at the top), (ends on the well side only), and at Reading (family values, not upper bounds on ) LeanK_ff_C2, K_ff_C4 (assumptions: the measured values of and ; arithmetic only). The value is the same at the three values of because does not enter the reduced model.
Step 4 Squeezing the ratio —
Dividing (13) by gives Proved here (division). From below, Proposition L (10-04 §04) gives Proved here (continuous time, ; the proof is placed in 10-04). Together,
. Proposition L is a lower bound that uses no conditions, and the left inequality of (14) does not depend on (H1)–(H4).
Step 5 The power form of H —
, and (14) gives . The remaining input is how the ruler grows, (for some and small ), which comes from . The semiclassical leading term of the continuum model is a copy of a known formula Cited, and for the lattice model it is a reading that settles to a constant, , at the three values of Reading (10-04 §07). On this input
and the power form of H follows Proved here Leanpower_H_of_kink_ratio (assumptions: , , , and and for . in Lean is in the text).
Checking the single line
Shrinking Steps 1–5 to one line gives
. Of the inputs written above the arrows, the assumption rows are (H1seg), (H2tube), (T0′P), (KG), (X), (MIXalt) and the premises of Step 0, and the rest are elementary algebra, known theorems or readings.
Here we also check that the statements of the assumption rows do not contain the quantities of the conclusion. The quantities of the conclusion are of the whole measure with and the ratio . (H1seg), (H2tube) and (T0′P) are constants of the measures of scraps, tubes and cores, (KG) is a constant of the reduced gas, (X) is a comparison of forms, and (MIXalt) is a quantity of correlation. None of them contains or . A form that puts the conclusion among the premises (a circle of dependence) does not appear in the way these steps are built (for how to check this, see 10-13).
To be precise, the conclusion of Proposition 4.5 is the first-step statement that "the relaxation time of Langevin dynamics grows as a power of ". is a different quantity from the gap of the transfer operator (the tunnelling splitting), and even if every row of Proposition 4.5 were in place, the statements from the second step on would not follow (10-01 §08, 10-03 §06).
The distance from known theorems
Within the range searched, no known theorem gives the upper bound (5) of Proposition 4.5. Table 1 summarises how far nearby theorems reach and where they stop.
| Known theorem | Where it reaches | Where it does not | Grade |
|---|---|---|---|
| The Poincaré version of Eyring–Kramers (Bovier–Gayrard–Klein; Menz–Schlichting Lemma 2.4, Theorems 2.9 and 2.12) | For a Morse function at fixed dimension, from the splitting of the variance, local Poincaré and transport of the mean difference up to the asymptotics of the gap and the prefactor | The constants are not uniform in the dimension. Degenerate families of saddles such as translation of a kink are outside the assumptions | Cited |
| Eyring–Kramers for the stochastic Allen–Cahn equation on a fixed interval (Di Gesù–Le Peutrec; Brooks–Di Gesù) | Asymptotics of the gap with the length of the interval fixed below the bifurcation threshold | The regime with infinite interval length and the translation family are stated by the authors themselves in the text to be out of scope | Cited |
| Transition times of short paths (Berglund–Gentz Theorem 2.6) | The mean time to move between valleys for (uniform saddle) | Long paths () | Cited |
| Diffusion of a single interface (Bertini–Brassesco–Buttà Theorem 2.1) | That the position of a single kink approaches Brownian motion with diffusion coefficient (at the level of the process) | Not a statement about the spectral gap of the whole path | Cited |
| A criterion uniform in the volume (Bauerschmidt–Dagallier Theorem 2.1) | Applies directly to the lattice of paths and gives an upper bound uniform in the volume | The value is with (, ), doubly exponential in . It does not reach the power form of H | Cited (theorem) Reading (value) |
| Box dynamics (Propositions 3.4 and 3.5 of Martinelli's lectures) | For discrete spins, the type that controls the whole gap by the box dynamics and the gap inside the box | Unbounded spins, over boundary values. Step 1 borrows only the type, rewritten in one dimension in the form | Cited (type) |
As the last three rows of Table 1 show, the known tools sit at the two ends, "a single kink" and "an upper bound uniform in the volume but coarse", and what lies between them (an upper bound on long paths sharp up to the diffusion time of the kink gas) is the place of Proposition 4.5. The Bauerschmidt–Dagallier bound becoming is read as follows: the criterion looks at a single quantity, the susceptibility, so it cannot distinguish slow but local relaxation from slow and global relaxation, and enters the exponent Reading.
The table of the five grades — the rows of the steps of Proposition 4.5
We put the steps of §04 into one table in the format of the five grades (10-00 §01). Each row has one grade, and the column of machine checking is outside the grades. The symbols of the rows correspond to the numbers of the nodes of the dependency graph in §07.
| Row | Statement (one line) | Grade | Grounds | Range of | Machine checking |
|---|---|---|---|---|---|
| P0 | Uniqueness of the measure with , the step of the limit, regularity | Assumption | §04 Step 0 (the original source for the principal eigenvalue of a positive kernel on is unchecked) | — | — |
| H1s | (H1seg) Poincaré of scraps without kinks uniform in the length, the end values and | Assumption | §03, (10) of §04 Step 2. The node propositions for the ring version are in 10-06 | — | — |
| H2t | (H2tube) Poincaré of the tube uniform in length | Assumption | §03, (10) | — | — |
| T0P | (T0′P) Poincaré of the core uniform in the core length | Assumption | §03, (10). The proposition with an assumption at the lower end of the window is in 10-09 and 10-11 | — | — |
| KG | (KG) The box gap of the reduced kink gas | Assumption | §04 Step 2 (the assumption that it falls into the Glauber type) | — | — |
| X | (X) Cross term | Assumption | §04 Step 2 | — | — |
| MIX | (MIXalt) uniformly in | Assumption | §04 Step 1 | — | — |
| Mob | Mobility of a single kink | Cited | §02 (d), 10-04 §03 (a copy of the coefficient of a theorem at the level of the process) | — | |
| TP | Lemma TP (two projections) | Proved here | Proof in §04 Step 1 | Independent of | two_proj_var (assumption: ) |
| ES | Conditional independence of even boxes and the product variance inequality (7) | Proved here | §04 Step 1 (proof in 10-11) | Independent of | — |
| H3 | Proposition H3: (8) | Proved here | §04 Step 1 (TP, ES, averaging over shifts) | Independent of | box_two_family, box_shift_average (assumptions: two-family inequality, , sum over overlaps ) |
| DEC | Decomposition of the variance (9) and into a product (10) | Proved here | §04 Step 2 (the product decomposition depends on how is defined; regularity is in P0) | Independent of | — |
| KGc | (the algebra of (11)) | Proved here | §04 Step 2 (the closed Glauber formula is inside (KG)) | Independent of | kg_constant (assumption: ) |
| H4 | Proposition H4: (12) | Proved here | §04 Step 2 | Independent of | H4_two_scale, H4_gap_form (assumptions are the rows of §04 Step 2) |
| P45 | Proposition 4.5: (13) | Proved here | §04 Step 3 | H3_H4_compose (assumptions: (8), (12), , , ) | |
| Kv | (), () | Reading | §04 Step 3 (reduced model, , family values) | Independent of | K_ff_C2, K_ff_C4 (assumptions: measured values; arithmetic only) |
| L | Proposition L: | Proved here | 10-04 §04 | Every | local_rayleigh_ratio_le_one (the skeleton of the finite sum only; the assumptions are in Table 3 of 10-04) |
| Rb | (14) | Proved here | §04 Step 4 | — | |
| Xi | () | Reading | §04 Step 5 (the continuum leading term is Cited, the values of the lattice model are Reading) | Read at three points; from the leading term | — |
| PH | The power form of H: | Proved here | (15) of §04 Step 5 | power_H_of_kink_ratio (assumptions: , , ) |
The "Proved here" rows of Table 2 are all algebra that takes assumption rows as input. That "Proved here" rows line up does not mean that the conclusion of Proposition 4.5 has been shown. The conclusion becomes unconditional only when every "Assumption" row and the "Reading" row (Xi) have been replaced.
The dependency graph — checking by the numbers that there is no circle
We turn the rows of Table 2 into a list of numbered nodes. The format is common to this part (the integrated graph of 10-12 is the same), and the numbers of the premises to the right of "⟸" are always placed smaller than the number of the conclusion on the left. The leaves (assumptions, known results, readings) have small numbers, and the conclusion has the largest number.
[01] ASM P0 uniqueness of the T=∞ measure, limit step, regularity ħ: —
[02] ASM (H1seg) Poincaré of scraps without kinks ħ: —
[03] ASM (H2tube) Poincaré of the tube (length ≤ Cξ) ħ: —
[04] ASM (T0'P) Poincaré of the core (uniform in core length) ħ: —
[05] ASM (KG) box gap of the reduced kink gas ħ: —
[06] ASM (X) cross term ℰ_Y ≤ (1+χ)ℰ ħ: —
[07] ASM (MIXalt) alternating maximal correlation c_alt < 1 ħ: —
[08] CIT Mob mobility of a single kink D = ħ/S₀ ħ→0
[09] RDG Xi ln ξ ≥ s/ħ (ξ ∝ ħ^½ e^(S₀/ħ)) three points, leading term
[10] PRV TP lemma of two projections independent of ħ
Lean two_proj_var (assumption: A+B ≤ (1+c)V)
[11] PRV ES conditional independence of even boxes, product variance (7) ⟸ [01] independent of ħ
[12] PRV DEC decomposition of variance (9), into a product (10) ⟸ [01] independent of ħ
[13] PRV KGc c_kg = C²+π² (algebra of (11)) independent of ħ
Lean kg_constant (assumption: Cξ ≠ 0)
[14] PRV Prop H3 (8) ⟸ [07][10][11] independent of ħ
Lean box_two_family, box_shift_average (assumptions: two-family inequality, C_box ≥ 0, sum over overlaps ≤ ℰ)
[15] PRV Prop H4 (12) ⟸ [02][03][04][05][06][08][12][13] independent of ħ
Lean H4_two_scale, H4_gap_form (assumptions: decomposition, C_loc, (KG), (X), D > 0, η < 1 and others)
[16] PRV Prop 4.5 (13) C_P ≤ Kξ²S₀/ħ ⟸ [08][14][15] ħ→0
Lean H3_H4_compose (assumptions: (8), (12), D = ħ/S₀, n, ħ, S₀ > 0, c_alt < 1)
[17] PRV Prop L R ≥ 1 ⟸ [01] every ħ
Lean local_rayleigh_ratio_le_one (skeleton of the finite sum only)
[18] PRV (14) 1 ≤ R ≤ K'/ħ ⟸ [16][17] ħ→0
[19] PRV power H ln C_P / ln ξ → 2 ⟸ [09][18] ħ→0
Lean power_H_of_kink_ratio (assumptions: 0 < K, s, δ; 1 ≤ R ≤ K/ħ; s/ħ ≤ ln ξ)
How to check. In every row with "⟸", look to see that the numbers on the right are smaller than the number on the left. [11] and [12] use only [01], [14] uses [07][10][11], [15] uses [02]–[06][08][12][13], [16] uses [08][14][15], [17] uses [01], [18] uses [16][17], and [19] uses [09][18]. Every row keeps the rule. If the rule is kept, following the premises always lowers the number and eventually reaches a leaf, so there is no circle.
Among the leaves, "Assumption" covers the seven [01]–[07], "Cited" is [08], and "Reading" is [09]. The conclusion [16] of Proposition 4.5 depends on all of [01]–[08] (on [01] also through [11][12]), and the power form of H [19] depends further on [09]. Only Proposition L [17] depends on nothing but [01] and does not use (H1)–(H4).
To be precise, this graph is the dependency of the construction of the steps of Proposition 4.5, and it does not include the content of each assumption row (for example Proposition H1, which supports [02] at the nodes). Those are in the graphs of the chapters on each condition, and the graph that joins them all into one is the integrated graph of 10-12.
A that fits all, and where the four conditions stand
There is no at which all rows are in place. The node propositions of condition (H1) are at six points with , the conditional propositions that support the core row are at the lower end of the window, of order , and the two do not meet. (KG), (X) and (H2tube) are assumption rows at every . The band figure and the way of fitting them together are placed in 10-12.
We list where each of the four conditions stands, one line each. The details are in each chapter.
- Condition (H1) — Proposition H1 for the ring version: margin at the six nodes , with neighbours and ends in (computer-assisted). What remains is between the nodes, , ends , and the scrap version (10-06)
- Condition (H2) — a map split into seven routes. The condition on the chain outside the window is computer-assisted on the whole window , five steps of the sector framework are propositions, and for the one remaining proposition three strands stop at the curvature shortfall at one site at the top (10-07–10-10)
- Condition (H3) — Proposition H3 (§04 Step 1). (MIXalt) and the over boundary values remain (10-11)
- Condition (H4) — Proposition H4 (§04 Step 2). (X), (KG), (H1seg) and the core row remain, and the core constant is controlled in three steps (10-11)
This part is a study that chose Assumption H as its foothold, and Proposition 4.5 is one way of splitting to build the upper side of the first step. Other views are treated in Part 11.
What this chapter can say
| What is said | What is not said |
|---|---|
| Proved here The algebra of the splitting of the variance (3), Lemma TP, Proposition H3 (8), Proposition H4 (12), the composition (13), the squeeze of the ratio (14), the algebra to the power form of H (15). All are algebra on named assumption rows Lean (the assumptions are the rows of Table 2) | None of the assumption rows [01]–[07]. Hence neither (5) itself nor the power form of H for the first step |
| Proved here Proposition L: (uses no conditions) | Whether grows like or exponentially |
| Cited The diffusion coefficient of a single kink; how far known theorems reach (Table 1) | A known theorem giving an upper bound on long paths sharp up to the diffusion time of the kink gas (only as far as "not found within the range searched") |
| Reading and others (reduced model), , how grows | Using these in proofs of upper or lower bounds |
| That the dependency graph has no circle (the rule of the numbers) | A at which all rows are in place. Implications from the first step to the second and later steps |
Sources and reproduction
| Item | Kind | Source / tools |
|---|---|---|
| The splitting of the variance, the skeleton of the Poincaré version of Eyring–Kramers | Cited | G. Menz, A. Schlichting, Ann. Probab. 42 (2014), arXiv:1202.1510 (Lemma 2.4, Theorems 2.9 and 2.12; text checked). A. Bovier, V. Gayrard, M. Klein, J. Eur. Math. Soc. 7 (2005) 69–99 (bibliographic data). |
| Bakry–Émery on a convex region | Cited | D. Bakry, M. Émery, LNM 1123 (1985); A. V. Kolesnikov, E. Milman, J. Geom. Anal. 27 (2017), arXiv:1310.2526 (Theorem 1.2; text checked). |
| Eyring–Kramers on a fixed interval | Cited | G. Di Gesù, D. Le Peutrec, arXiv:1506.04434 (Theorem 1.1); M. Brooks, G. Di Gesù, arXiv:2606.16083 (the explicit statement of what is out of scope; text checked). |
| Transition times of short paths, diffusion of a single interface | Cited | The table of sources of 10-04 (Berglund–Gentz, Bertini–Brassesco–Buttà). |
| A criterion uniform in the volume | Cited, Reading | R. Bauerschmidt, B. Dagallier, Comm. Pure Appl. Math. 77, arXiv:2202.02295 (Theorem 2.1; text checked). The application to the lattice of paths and the value are floating-point computations of the record (transfer matrix, , 1.0049 on the harmonic positive control). |
| The type of box dynamics | Cited | F. Martinelli, LNM 1717 (1999) 93–191 (checked in §3.6 and Propositions 3.4 and 3.5 of the preprint). |
| The lemma of two projections, the Efron–Stein type | Proved here | §04 Step 1 of the text (the original sources for the Friedrichs angle and Efron–Stein are bibliographic only). |
| The closed formula for the box gap of Glauber dynamics, values with free ends | Assumption, Reading | R. J. Glauber, J. Math. Phys. 4 (1963) 294 (bibliographic only). The fixed-end formula agrees to 6 digits with diagonalisation over all states of small chains; free ends are lattice values (floating point). |
| Values of the alternating maximal correlation | Reading | Family values copied from the closed formula for the two-state telegraph chain (floating point). |
| The algebra of the steps | Proved here, Lean | Theorems split_poincare_le, reduced_two_state_value, two_proj_var, box_two_family, box_shift_average, kg_constant, H4_two_scale, H4_gap_form, H3_H4_compose, K_ff_C2, K_ff_C4, power_H_of_kink_ratio (the assumptions are the rows of Table 2 and of the text). The list of statements is in 10-13. |
Words used in this chapter — splitting of the variance, local Poincaré, transport of the mean difference, conditions (H1)–(H4), Proposition 4.5, phase (phase without kinks), scrap, tube, core, box dynamics (reduction to the box), maximal correlation, alternating maximal correlation, lemma of two projections, Efron–Stein inequality, reduced kink gas, cross term, dependency graph. Their meanings are in A-02 Glossary.
Next chapter to read: 10-06 (H1) Local Poincaré within a phase — turns the Poincaré constant of the measure of the phase without kinks into node propositions at six values of , by a two-scale construction of kept sites and bridges, and describes the method and cost of filling in between the nodes.
← 10-04 The path measure of the double well, and kinksContents10-06 (H1) Local Poincaré within a phase →