The constants of the weighted lattice #
The chosen configuration is the periodic measure with columns at x = i * hgap, carrying mass
1 for even i and mass heavy for odd i, and rows at y = j * vgap of unit weight. Its
parameters are determined by three edge collisions of witness rectangles; they reduce to the single
quadratic 3 u² - 4 u - 6 = 0 for u = root = (2 + √22)/3:
heavy = u² - 1 = (17 + 4√22)/9, so a light and a heavy atom together weighu²;hgap = (1 + u)/2 = (5 + √22)/6andvgap = hgap + 1 = (11 + √22)/6.
The witness squares use the sides 1, u, sideH1 = √heavy, sideLH2 = √2 · u,
sideLHL2 = √(2 (2 + heavy)) and 2 hgap + 1. The witnesses cover the period cell outside
four open slots, each of width slotW and height slotH, and
phi = (2 hgap vgap - 4 slotW slotH) / (1 + heavy).
All numerical facts are proved from rational enclosures of √2 and √22.
u = (2 + √22)/3, the positive root of 3u² - 4u - 6 = 0.
Equations
- LeanPool.CenteredMaximal.Lattice.root = (2 + √22) / 3
Instances For
The heavy mass w = u² - 1 = (17 + 4√22)/9.
Instances For
The column spacing h = (1 + u)/2 = (5 + √22)/6.
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The row spacing V = h + 1 = (11 + √22)/6.
Instances For
Side of the witness made of one heavy atom: √w.
Instances For
Side of the witness made of a light and a heavy atom in two rows: √(2(1 + w)) = √2 · u.
Instances For
Side of the witness made of light, heavy, light atoms in two rows: √(2(2 + w)).
Equations
Instances For
Width of a slot excluded from the witnessed region: 2h - √(2(2 + w))/2 - u/2.
Equations
Instances For
Height of a slot excluded from the witnessed region: V - √(2(1 + w))/2 - √w/2.
Equations
Instances For
Square roots #
Lower rational enclosure of √22.
Upper rational enclosure of √22.
Exact identities #
Numerical facts #
1 ≤ u, so the light–heavy one-row witness has side at least 1.
Lower enclosure of √(2(2 + w)).
Upper enclosure of √(2(2 + w)).
1 ≤ √w: the heavy atom's square reaches back to the light–heavy one-row region.
u ≤ √2 u: the light–heavy two-row witness is wider than the one-row one.