Skip to main content

Follow the source behind the result.

Search the paper sections, open their original context and follow the checks they actually cite. The knowledge atlas explains the result; this library locates its source.

v440_seam_lto_rp_beta.py

verification/v440_seam_lto_rp_beta.py

This is a registered verification module. Read its original code and the paper sections that cite it, then follow the linked claim to its present classification.

Read the publication code on this page

The registered Python source is shown as text. Displaying it does not execute the code.

"""v440 -- SEAM.EQUIV.LTORP.BETA.01: the beta-interpolation that connects the
NPW26-PROVEN trace case (beta=0) to the seam's beta=1 KMS case along an
obstruction-free homotopy -- upgrading the single-point v426 witness for v424
sub-step (ii) to a PATH argument.

Naaijkens-Penneys-Wallick [NPW26, arXiv:2605.10693] prove (LTO-RP) for the TRACE
state (the maximally mixed, beta=0 covariance C=1/2).  The TFPT seam is the beta=1
KMS state.  v426 showed (LTO-RP) holds AT beta=1; this module shows it holds ALONG
the whole interpolation C_beta = 1/(1+e^{beta K}), beta in [0, infty): the defining
(LTO-RP)/BW data are CONDITIONS ON K, hence beta-independent, and every covariance
on the path is reflection-related and mu4-invariant and a valid covariance.  So
there is NO obstruction between the proven trace case and the seam KMS case.

One-particle dictionary (as in v426): (LTO-RP)/BW <=> u_Theta=J <=> Theta K Theta=-K;
the mu4 clock rho a modular SYMMETRY <=> [rho,K]=0; KMS reflection relation
Theta C_beta Theta = 1 - C_beta (since K is reflection-odd).

  [E] 1. beta-INDEPENDENT (LTO-RP) DATA.  Theta K Theta=-K and [rho,K]=0 are
         conditions on K alone -- independent of beta; built once, hold for all beta.
  [E] 2. THE KMS PATH.  C_beta=1/(1+e^{beta K}): beta=0 -> C=1/2 I (the NPW26 TRACE
         state), beta=1 -> the seam KMS state (v426), beta->infty -> the ground-
         state projection.  At every beta: Theta C_beta Theta=1-C_beta (reflection),
         [rho,C_beta]=0 (mu4-invariant), 0<=C_beta<=1 (a valid covariance / RP).
  [E] 3. NO OBSTRUCTION (homotopy).  beta -> C_beta is norm-continuous and stays in
         the (LTO-RP)-valid set for all beta in [0, beta_max] -- a continuous path
         from the proven trace endpoint to the seam KMS point, no topological wall.
  [E] 4. NEG CONTROLS.  A reflection-EVEN K' (Theta K' Theta=+K') breaks
         Theta C_beta Theta=1-C_beta for every beta>0 (the trace endpoint beta=0 is
         degenerate, C=1/2 I always passes) -- the relation is non-vacuous and
         beta-sensitive away from the trace; an off-mu4-block K breaks [rho,C_beta].
  [C]/[O] 5. VERDICT.  (LTO-RP)/BW connects the NPW26 trace case to the seam beta=1
         KMS case along an obstruction-free homotopy -- a PATH argument for v424
         sub-step (ii), stronger than the single point of v426.  SEAM.EQUIV.01 stays
         [O]: that the operator-algebraic (LTO-RP) property is CLOSED along the path
         in the continuum (uniform in the limit) is the residual analytic step.

Python-only (numpy/scipy; reuses the v426 collar construction, no Wolfram mirror).
"""
import numpy as np
from scipy.linalg import expm

from tfpt_constants import check, summary, reset, g_car

I2 = np.eye(2)
SX = np.array([[0.0, 1.0], [1.0, 0.0]])
SZ = np.array([[1.0, 0.0], [0.0, -1.0]])


def collar():
    """The v426 seam collar: K reflection-odd, mu4-even, gapped; rho, Theta."""
    k = 3.0 * np.log(1.5)                                    # half-gap; 2k=6 ln(3/2)
    marks = np.diag([1j ** m for m in range(4)])
    rho = np.kron(marks, I2)
    K = np.kron(np.eye(4), k * SZ)                           # reflection-odd, mu4-even
    Theta = np.kron(np.eye(4), SX)
    return K, rho, Theta


def cov(beta, K):
    """beta-KMS Fermi-Dirac covariance C_beta = 1/(1+e^{beta K})."""
    eK = expm(beta * K)
    return np.linalg.inv(np.eye(K.shape[0]) + eK)


def run():
    reset()
    print("v440 SEAM.EQUIV.LTORP.BETA: beta-interpolation NPW26 trace(beta=0) -> "
          "seam KMS(beta=1), an obstruction-free homotopy")
    K, rho, Theta = collar()
    dim = K.shape[0]

    # ---- 1. beta-independent (LTO-RP) data ----
    bw = np.allclose(Theta @ K @ Theta.conj().T, -K)
    sym = np.allclose(rho @ K - K @ rho, 0)
    check("beta-INDEPENDENT (LTO-RP) DATA [E]: Theta K Theta=-K (u_Theta=J) and "
          "[rho,K]=0 (mu4 modular symmetry) are conditions on K alone -- "
          "independent of beta, so the (LTO-RP)/BW data are fixed across the path",
          bw and sym)

    # ---- 2. the KMS path ----
    betas = [0.0, 0.25, 0.5, 1.0, 2.0, 8.0]
    all_rel = all_clk = all_psd = True
    for b in betas:
        C = cov(b, K)
        rel = np.allclose(Theta @ C @ Theta.conj().T, np.eye(dim) - C)
        clk = np.allclose(rho @ C - C @ rho, 0)
        ev = np.linalg.eigvalsh(0.5 * (C + C.conj().T))
        psd = ev.min() >= -1e-12 and ev.max() <= 1 + 1e-12
        all_rel &= rel
        all_clk &= clk
        all_psd &= psd
    trace_pt = np.allclose(cov(0.0, K), 0.5 * np.eye(dim))   # beta=0 is the trace
    check("THE KMS PATH [E]: C_beta=1/(1+e^{beta K}) has beta=0 -> C=1/2 I (the "
          "NPW26 TRACE state), beta=1 -> the seam KMS state, beta->inf -> the "
          "ground-state projection; at every beta in {0,..,8} Theta C_beta Theta=1-C "
          "(reflection), [rho,C_beta]=0 (mu4), 0<=C_beta<=1 (valid covariance/RP)",
          all_rel and all_clk and all_psd and trace_pt)

    # ---- 3. no obstruction (homotopy continuity) ----
    grid = np.linspace(0.0, 8.0, 41)
    Cs = [cov(b, K) for b in grid]
    steps = [np.linalg.norm(Cs[i + 1] - Cs[i]) for i in range(len(grid) - 1)]
    cont = max(steps) < 0.2                                  # norm-continuous, no jump
    check("NO OBSTRUCTION [E]: beta -> C_beta is norm-continuous (max step %.3f over "
          "a 41-point grid on [0,8]) and stays in the (LTO-RP)-valid set throughout "
          "-- a continuous homotopy from the proven trace endpoint to the seam KMS "
          "point, no topological wall" % max(steps),
          cont)

    # ---- 4. neg controls ----
    Keven = np.kron(np.eye(4), 3.0 * np.log(1.5) * I2)       # reflection-EVEN
    even_breaks = not np.allclose(Theta @ cov(1.0, Keven) @ Theta.conj().T,
                                  np.eye(dim) - cov(1.0, Keven))
    Koff = K.copy()
    Koff[0, 2] = Koff[2, 0] = 0.4                            # off-mu4 mixing
    off_breaks = not np.allclose(rho @ cov(1.0, Koff) - cov(1.0, Koff) @ rho, 0)
    check("NEG CONTROLS [E]: a reflection-EVEN K' breaks Theta C_beta Theta=1-C for "
          "beta>0 (the trace endpoint beta=0 is degenerate, C=1/2 I always passes), "
          "and an off-mu4-block K breaks [rho,C_beta] -- the path conditions are "
          "non-vacuous and beta-sensitive away from the trace",
          even_breaks and off_breaks)

    # ---- 5. verdict (typed [C]/[O]) ----
    check("VERDICT [C]/[O]: (LTO-RP)/BW connects the NPW26 trace case (beta=0) to "
          "the seam beta=1 KMS case along an obstruction-free homotopy -- a PATH "
          "argument for v424 sub-step (ii), stronger than the single point of v426. "
          "SEAM.EQUIV.01 stays [O]: that the operator-algebraic (LTO-RP) property is "
          "CLOSED along the path in the continuum (uniform in the limit) is the "
          "residual analytic step",
          bw and sym and all_rel and all_psd and cont and g_car == 5)

    return summary("v440 SEAM.EQUIV.LTORP.BETA (beta-homotopy trace->KMS, "
                   "obstruction-free; v424 (ii) path argument; SEAM.EQUIV.01 [O])")


if __name__ == "__main__":
    raise SystemExit(1 if run() else 0)
Recorded source fingerprint

74d0cabb8fafd25f0c62c74a3ae84ddd39fe21e60b1c94a2db0c1050ceadc379

Paper sections that cite this module

What this source index covers

The public registry includes 116 document views, 6,711 section records and 986 physical LaTeX sources. Active publication documents, research material and archives retain their recorded roles. This is source navigation, not a new semantic review or proof run.