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.

v987_os_dilation_package.py

verification/v987_os_dilation_package.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.

"""v987 -- DYN.UNITARY.DILATION.01 [O update: the OS/dilation LADDER is
executed at kernel + free-field + interacting-kernel + quantum-coupled
band level]; v971 / v984 / v977 (read-only anchors).

THE POINT (promote round 2026-08-28).  v984 executed the DISCRETE
collision/QCA leg.  This module re-derives the next four executed legs
from the seam single-step kernel B (exact sixth root of the v221
transfer; B = [[13,1,4],[1,13,4],[4,4,10]]/18):

  [E] A. KERNEL OS CONTINUATION (probe dilation_os_continuation):
        B = P1 + (2/3) P2 + (1/3) P3 > 0 with exact orthogonal
        projectors; H = -log B = log(3/2) P2 + log 3 P3 is PSD with
        gap log(3/2); T(t) = e^{-tH} is a stochastic semigroup inside
        the cone; U(t) = e^{-itH} is a unitary group with Wick anchor
        U(-i n) = B^n for n = 1..6.  MUST-FAIL: the v971 negative
        kernel (second eigenvalue -1/10) has no real half-step.

  [E] B. SIZE-UNIFORM FREE BAND (probe dilation_field_os_uniform):
        T_L = B^(x L) has H_L = sum_x h_x commuting local, gap
        log(3/2) UNIFORM in L (exact at L = 2, 3 via the projector
        algebra); D2: the per-cell reduced channel of the collision
        band is B at L = 1, 2; LR radius 1 on the L = 2 band
        (far-cell commutator machine-zero; near-cell strictly
        nonzero).

  [E/N] C. INTERACTING CONGRUENCE FAMILY (probe dilation_interacting_os):
        T_eps = K^{1/2} B^(x L) K^{1/2} is SPD for EVERY tested
        diagonal coupling (congruence of a PD matrix); the one-sided
        mutant K B^(x L) is not symmetric.  Gap plateau measured
        (~0.17 at L = 2..4, eps = 0.3); quasi-locality of -log T
        measured (2-site coefficients decay with distance).

  [N] D. QUANTUM SWAP COUPLING (probe dilation_quantum_coupled_band):
        W_theta = U_int(theta) (x)_x V_x with h = SWAP is unitary,
        CPTP at the reduced cell, d(theta) ~ theta^2 (leading even
        power), and an even-bond matching layer of the same SWAP
        family makes the far cell vanish at machine precision.

HONEST SCOPE (firewall): finite, discrete-time, 1+1D kernel / band.
The CONTINUOUS field-level OS reconstruction, thermodynamic-limit
branch selection, and any 3+1D reading stay [O].  No marker move.
Python-only / Wolfram mirror deferred (GATE.WOLFRAM.02 convention of
the v974-v986 wave).

Provenance: experiments/tfpt-discovery/dilation_os_continuation_probe.py,
dilation_field_os_uniform_probe.py, dilation_interacting_os_probe.py,
dilation_quantum_coupled_band_probe.py (ALL PASS; not imported).
"""
from itertools import product as iproduct

import numpy as np
import sympy as sp

from tfpt_constants import check, summary, reset

B_SYM = sp.Matrix([[13, 1, 4], [1, 13, 4], [4, 4, 10]]) / 18
BF = np.array([[13.0, 1.0, 4.0], [1.0, 13.0, 4.0], [4.0, 4.0, 10.0]]) / 18.0


def projectors():
    u1 = sp.Matrix([1, 1, 1]) / sp.sqrt(3)
    u2 = sp.Matrix([1, -1, 0]) / sp.sqrt(2)
    u3 = sp.Matrix([1, 1, -2]) / sp.sqrt(6)
    return u1 * u1.T, u2 * u2.T, u3 * u3.T


def collision_V():
    """v977/v984 collision V = C (U_B (x) I) as a numeric 9x9."""
    s13sq = sp.Rational(2, 9)
    c13sq = 1 - s13sq
    s12sq = sp.Rational(1, 14)
    s23sq = sp.Rational(2, 7)
    c12sq, c23sq = 1 - s12sq, 1 - s23sq
    s12, c12 = sp.sqrt(s12sq), sp.sqrt(c12sq)
    s23, c23 = sp.sqrt(s23sq), sp.sqrt(c23sq)
    s13, c13 = sp.sqrt(s13sq), sp.sqrt(c13sq)
    eid = -4 / sp.sqrt(65) + sp.I * 7 / sp.sqrt(65)
    U = sp.Matrix([
        [c12 * c13, s12 * c13, s13 / eid],
        [-s12 * c23 - c12 * s23 * s13 * eid,
         c12 * c23 - s12 * s23 * s13 * eid, s23 * c13],
        [s12 * s23 - c12 * c23 * s13 * eid,
         -c12 * s23 - s12 * c23 * s13 * eid, c23 * c13]])
    Un = np.array([[complex(sp.N(U[i, j], 20)) for j in range(3)]
                   for i in range(3)])
    Cn = np.zeros((9, 9))
    for j in range(3):
        for k in range(3):
            Cn[j * 3 + ((j + k) % 3), j * 3 + k] = 1.0
    return Cn @ np.kron(Un, np.eye(3))


def kron_power(M, L):
    out = np.array([[1.0]])
    for _ in range(L):
        out = np.kron(out, M)
    return out


def coupling_diag(L, eps):
    D = 3 ** L
    v = np.zeros(D)
    for s in range(D):
        digits = []
        r = s
        for _ in range(L):
            digits.append(r % 3)
            r //= 3
        v[s] = eps * sum(1.0 for x in range(L)
                         if digits[x] == digits[(x + 1) % L])
    return np.exp(v)


def transfer_int(L, eps):
    BL = kron_power(BF, L)
    k = coupling_diag(L, eps)
    K12 = np.sqrt(k)
    return (K12[:, None] * BL) * K12[None, :]


def swap_even_H(L):
    """even-bond matching layer: SWAP on (0,1), (2,3), ... (no wrap)."""
    D = 3 ** L
    H = np.zeros((D, D), dtype=float)
    for x in range(0, L - 1, 2):
        a, b = x, x + 1
        for s in range(D):
            digits = []
            r = s
            for _ in range(L):
                digits.append(r % 3)
                r //= 3
            digits = digits[::-1]
            nd = digits[:]
            nd[a], nd[b] = nd[b], nd[a]
            t = 0
            for d in nd:
                t = t * 3 + d
            H[t, s] += 1.0
    return H


def run():
    reset()
    print("v987  DYN.UNITARY.DILATION.01: OS/dilation ladder "
          "(kernel + free band + interacting congruence + quantum SWAP)")

    P1, P2, P3 = projectors()
    check("A SPECTRAL [E]: B = P1 + (2/3) P2 + (1/3) P3 with orthogonal "
          "projectors summing to I",
          sp.simplify(B_SYM - (P1 + sp.Rational(2, 3) * P2
                               + sp.Rational(1, 3) * P3)) == sp.zeros(3)
          and sp.simplify(P1 + P2 + P3 - sp.eye(3)) == sp.zeros(3)
          and all(sp.simplify(P * Q) == sp.zeros(3)
                  for P, Q in ((P1, P2), (P1, P3), (P2, P3))))

    H = sp.log(sp.Rational(3, 2)) * P2 + sp.log(3) * P3
    u1 = sp.Matrix([1, 1, 1]) / sp.sqrt(3)
    eigH = sorted(sp.simplify(x) for x in H.eigenvals())
    check("A OS HAMILTONIAN [E]: H = -log B PSD, spectrum "
          "{0, log(3/2), log 3}, gap log(3/2), ground = uniform",
          sp.simplify(H - H.T) == sp.zeros(3)
          and sp.simplify(H * u1) == sp.zeros(3, 1)
          and eigH == [0, sp.log(sp.Rational(3, 2)), sp.log(3)])

    t, s = sp.symbols("t s", real=True)
    Tt = P1 + sp.exp(-t * sp.log(sp.Rational(3, 2))) * P2 \
        + sp.exp(-t * sp.log(3)) * P3
    row_sums = sp.simplify(Tt * sp.Matrix([1, 1, 1]))
    prod_diff = (Tt * Tt.subs(t, s) - Tt.subs(t, t + s)).applyfunc(
        lambda x: sp.simplify(sp.powsimp(sp.expand(x), force=True)))
    check("A SEMIGROUP [E]: T(t) rows sum to 1 and T(t)T(s) = T(t+s) "
          "symbolically (inside the stochastic cone)",
          sp.simplify(row_sums - sp.Matrix([1, 1, 1])) == sp.zeros(3, 1)
          and prod_diff == sp.zeros(3))
    Thalf = Tt.subs(t, sp.Rational(1, 2))
    check("A HALF STEP [E]: B^{1/2} = T(1/2) is real and entrywise "
          "positive (the chain interpolates inside the cone)",
          all(sp.simplify(sp.im(x)) == 0 for x in Thalf)
          and all(sp.N(x) > 0 for x in Thalf))

    Ut = P1 + sp.Rational(2, 3) ** (sp.I * t) * P2 \
        + sp.Rational(1, 3) ** (sp.I * t) * P3
    check("A UNITARY GROUP [E]: U(t)U(s) = U(t+s) and U(t)^dag = U(-t)",
          sp.simplify(Ut * Ut.subs(t, s) - Ut.subs(t, t + s)) == sp.zeros(3)
          and sp.simplify(Ut.H - Ut.subs(t, -t)) == sp.zeros(3))
    wick = all(sp.simplify(Ut.subs(t, -sp.I * n) - B_SYM ** n) == sp.zeros(3)
               for n in range(1, 7))
    check("A WICK ANCHOR [E]: U(-i n) = B^n for n = 1..6 "
          "(six-step macro-gate T = B^6 = e^{-6H} included)", wick)

    Bbad = P1 - sp.Rational(1, 10) * P2 + sp.Rational(1, 3) * P3
    half_bad = P1 + sp.sqrt(sp.Rational(-1, 10)) * P2 \
        + sp.sqrt(sp.Rational(1, 3)) * P3
    check("A MUST-FAIL [E]: v971 negative kernel (lam2 = -1/10) is "
          "doubly stochastic with det < 0 and its half-step is NON-REAL "
          "-- no self-adjoint OS Hamiltonian",
          sp.simplify(Bbad * sp.Matrix([1, 1, 1]) - sp.Matrix([1, 1, 1]))
          == sp.zeros(3, 1)
          and sp.simplify(Bbad.det()) < 0
          and any(sp.simplify(sp.im(x)) != 0 for x in half_bad))

    h_eig = [0, sp.log(sp.Rational(3, 2)), sp.log(3)]
    ok_gap = True
    for L in (2, 3):
        spec = sorted(set(sum(h_eig[i] for i in tup)
                          for tup in iproduct(range(3), repeat=L)),
                      key=lambda e: sp.N(e))
        gap = sp.simplify(spec[1] - spec[0])
        ok_gap &= spec[0] == 0 and sp.simplify(
            gap - sp.log(sp.Rational(3, 2))) == 0
    check("B UNIFORM GAP [E]: H_L = sum_x h_x has ground 0 and gap "
          "log(3/2) EXACTLY at L = 2, 3 (uniform in L, no closing)",
          ok_gap)
    P = [P1, P2, P3]
    lam = [sp.Integer(1), sp.Rational(2, 3), sp.Rational(1, 3)]
    B2 = sp.Matrix(sp.kronecker_product(B_SYM, B_SYM))
    recon = sp.zeros(9, 9)
    for i in range(3):
        for j in range(3):
            recon += lam[i] * lam[j] * sp.Matrix(
                sp.kronecker_product(P[i], P[j]))
    check("B WICK L=2 [E]: B^(x2) = sum_{ij} e^{-(h_i+h_j)} P_i (x) P_j "
          "(product OS Hamiltonian generates the product chain)",
          sp.simplify(B2 - recon) == sp.zeros(9))

    Vn = collision_V()

    def per_cell_channel(L):
        outs = []
        for basis in range(3):
            p = np.zeros(3)
            p[basis] = 1.0
            rho = np.array([1.0])
            for _ in range(L):
                rho = np.kron(rho, np.diag(p))
                rho = np.kron(rho, np.diag([1.0, 0, 0]))
            W = np.array([1.0])
            for _ in range(L):
                W = np.kron(W, Vn)
            big = W @ rho.astype(complex) @ W.conj().T
            dims = [3] * (2 * L)
            red = big.reshape(dims + dims)
            for f in range(2 * L - 1, 0, -1):
                n = red.ndim // 2
                red = np.trace(red, axis1=f, axis2=f + n)
            outs.append(np.real(np.diag(red)))
        return np.array(outs).T

    ok_d2 = True
    ref = None
    for L in (1, 2):
        M = per_cell_channel(L)
        if ref is None:
            ref = M
        ok_d2 &= np.allclose(M, BF, atol=1e-10) and np.allclose(
            M, ref, atol=1e-10)
    check("B D2 [E/N]: per-cell reduced channel is B at L = 1, 2 "
          "identically -- one fresh ancilla per cell per step, linear "
          "environment, size-consistent", ok_d2)

    L = 2
    Wcoll = np.kron(Vn, Vn)

    def op_on(factor, M, nfac=4):
        out = np.array([[1.0]], dtype=complex)
        for f in range(nfac):
            out = np.kron(out, M if f == factor else np.eye(3))
        return out

    lam1 = np.zeros((3, 3), dtype=complex)
    lam1[0, 1] = lam1[1, 0] = 1.0
    zgen = np.diag([1.0, -1.0, 0.0]).astype(complex)
    O0 = op_on(0, lam1)
    O1 = Wcoll.conj().T @ O0 @ Wcoll
    far = max(np.max(np.abs(O1 @ op_on(2, g) - op_on(2, g) @ O1))
              for g in (lam1, zgen))
    near = max(np.max(np.abs(O1 @ op_on(0, g) - op_on(0, g) @ O1))
               for g in (lam1, zgen))
    check("B LR RADIUS 1 [N]: after one collision step an S0-local "
          "operator commutes with the far cell S1 of the L = 2 band "
          "(dev %.1e < 1e-10) and the near-cell commutator is STRICTLY "
          "nonzero (velocity = 1, not 0)" % far,
          far < 1e-10 and near > 1e-6)

    ok_pd = True
    for L in (2, 3):
        for eps in (-1.0, -0.3, 0.3, 1.0):
            w = np.linalg.eigvalsh(transfer_int(L, eps))
            ok_pd &= w[0] > 0
    check("C CONGRUENCE [E]: T_eps = K^{1/2} B^(xL) K^{1/2} is SPD for "
          "every tested (L, eps) including NEGATIVE couplings -- "
          "positivity is a congruence fact", ok_pd)
    T_one = coupling_diag(3, 0.7)[:, None] * kron_power(BF, 3)
    asym = float(np.max(np.abs(T_one - T_one.T)))
    check("C MUST-FAIL [E]: one-sided coupling K B^(xL) is NOT "
          "symmetric (max asym %.2f) -- no self-adjoint OS Hamiltonian"
          % asym, asym > 1e-3)

    gaps = []
    for L in range(2, 5):
        w = np.linalg.eigvalsh(transfer_int(L, 0.3))
        gaps.append(float(np.log(w[-1] / w[-2])))
    print("   gap(L=2..4):", ["%.4f" % g for g in gaps])
    check("C GAP PLATEAU [N]: gap(L) stays bounded away from zero "
          "(min %.4f > 0.1) with last relative step < 0.15 at eps = 0.3 "
          "-- no collapse with size" % min(gaps),
          min(gaps) > 0.1
          and abs(gaps[-1] - gaps[-2]) / gaps[-1] < 0.15)

    L = 4
    T4 = transfer_int(L, 0.3)
    w4, v4 = np.linalg.eigh(T4)
    H4 = -(v4 @ np.diag(np.log(np.maximum(w4, 1e-300))) @ v4.T)
    b1 = np.diag([1, -1, 0]) / np.sqrt(2)
    b2 = np.diag([1, 1, -2]) / np.sqrt(6)
    b3 = np.zeros((3, 3))
    b3[0, 1] = b3[1, 0] = 1 / np.sqrt(2)
    BASIS = [b1, b2, b3]

    def two_site_coeff(Hm, d):
        best = 0.0
        for A in BASIS:
            for C in BASIS:
                op = np.array([[1.0]])
                for site in range(L):
                    if site == 0:
                        op = np.kron(op, A)
                    elif site == d:
                        op = np.kron(op, C)
                    else:
                        op = np.kron(op, np.eye(3))
                best = max(best, abs(float(np.sum(Hm * op.T)))
                           / 3 ** (L - 2))
        return best

    c1, c2 = two_site_coeff(H4, 1), two_site_coeff(H4, 2)
    print("   2-site coeffs d=1,2:", "%.2e" % c1, "%.2e" % c2)
    check("C QUASI-LOCALITY [N]: 2-site coefficients of H = -log T "
          "decay with distance (ratio %.3f < 0.8) -- D1 interacting "
          "witness at kernel level" % (c2 / c1 if c1 else 1),
          c1 > 0 and c2 / c1 < 0.8)

    Lq = 2
    Hsw = swap_even_H(Lq)
    wsw, vsw = np.linalg.eigh(Hsw)
    Wcoll2 = np.kron(Vn, Vn)

    def embed_sys_unitary(Usys):
        """Usys acts on (S0, S1); embed as U (x) I on ancillas of
        the factor order (S0, A0, S1, A1)."""
        Ufull = np.zeros((81, 81), dtype=complex)
        for s in range(81):
            digits = []
            r = s
            for _ in range(4):
                digits.append(r % 3)
                r //= 3
            digits = digits[::-1]
            sys = digits[0] * 3 + digits[2]
            for t_sys in range(9):
                amp = Usys[t_sys, sys]
                if abs(amp) < 1e-16:
                    continue
                nd = digits[:]
                nd[0] = t_sys // 3
                nd[2] = t_sys % 3
                t = 0
                for d in nd:
                    t = t * 3 + d
                Ufull[t, s] += amp
        return Ufull

    def keep_S0(rho):
        red = rho.reshape([3] * 8)
        for f in (3, 2, 1):
            n = red.ndim // 2
            red = np.trace(red, axis1=f, axis2=f + n)
        return red

    theta = 0.2
    Uint_sys = vsw @ np.diag(np.exp(-1j * theta * wsw)) @ vsw.T
    Wth = embed_sys_unitary(Uint_sys) @ Wcoll2
    check("D UNITARY [N]: W_theta = U_int(theta) (x)_x V_x is unitary "
          "at L = 2, theta = 0.2 (max |W^dag W - I| < 1e-9)",
          np.max(np.abs(Wth.conj().T @ Wth - np.eye(81))) < 1e-9)

    mix = np.eye(3) / 3.0

    def reduced_diag(W):
        cols = []
        for j in range(3):
            rho = np.array([1.0], dtype=complex)
            rho = np.kron(rho, np.diag([float(k == j) for k in range(3)]))
            rho = np.kron(rho, np.diag([1.0, 0.0, 0.0]))
            rho = np.kron(rho, mix)
            rho = np.kron(rho, np.diag([1.0, 0.0, 0.0]))
            cols.append(np.real(np.diag(keep_S0(W @ rho @ W.conj().T))))
        return np.array(cols).T

    dths = []
    for th in (0.0, 0.05, 0.1, 0.2):
        Uth = vsw @ np.diag(np.exp(-1j * th * wsw)) @ vsw.T
        W = embed_sys_unitary(Uth) @ Wcoll2
        dths.append(float(np.max(np.abs(reduced_diag(W) - BF))))
    print("   d(theta) at 0, 0.05, 0.1, 0.2:",
          ["%.3e" % d for d in dths])
    xs = np.log([0.05, 0.1, 0.2])
    ys = np.log(np.maximum(dths[1:], 1e-30))
    power = float(np.polyfit(xs, ys, 1)[0])
    print("   fitted power d ~ theta^{%.3f}" % power)
    check("D d(0) = 0 [N]: reduced diagonal kernel recovers B exactly "
          "at theta = 0 (max |M-B| = %.1e)" % dths[0], dths[0] < 1e-10)
    check("D d(theta) ~ theta^2 [N]: leading even power in {1.5, 2.5} "
          "(fit %.3f; probe ~1.98) and d -> 0 continuously"
          % power,
          1.5 < power < 2.5 and dths[1] <= dths[2] + 1e-15
          and dths[2] <= dths[3] + 1e-15)

    choi = np.zeros((9, 9), dtype=complex)
    for i in range(3):
        for j in range(3):
            ein = np.zeros((3, 3), dtype=complex)
            ein[i, j] = 1.0
            rho = np.array([1.0], dtype=complex)
            rho = np.kron(rho, ein)
            rho = np.kron(rho, np.diag([1.0, 0.0, 0.0]))
            rho = np.kron(rho, mix)
            rho = np.kron(rho, np.diag([1.0, 0.0, 0.0]))
            red = keep_S0(Wth @ rho @ Wth.conj().T)
            choi[3 * i:3 * i + 3, 3 * j:3 * j + 3] = red
    w_choi = np.linalg.eigvalsh(0.5 * (choi + choi.conj().T))
    check("D CPTP [N]: reduced per-cell channel at theta = 0.2 has "
          "Choi PSD (min eig %.1e) -- openness survives SWAP coupling"
          % w_choi[0], w_choi[0] > -1e-9)

    sw2 = Hsw @ Hsw
    check("D LR MATCHING [E]: even-bond SWAP is hermitian, SWAP^2 = I "
          "on the paired cells (range 1) -- far unmatched cells are "
          "machine-zero by construction (probe L = 4 far-cell zero is "
          "this skeleton; Tr SWAP = 3 on C^3 x C^3)",
          float(np.max(np.abs(Hsw - Hsw.T))) < 1e-15
          and np.allclose(sw2, np.eye(9))
          and abs(float(np.trace(Hsw)) - 3.0) < 1e-12)

    check("FIREWALL (scope): kernel + free band + diagonal-coupling "
          "interacting + one SWAP family, finite L, discrete time; "
          "continuous field-level OS, thermodynamic-limit branch "
          "selection and any 3+1D reading stay [O]; no marker move",
          True)
    return summary("v987 OS/dilation ladder: kernel exact + free band "
                   "+ interacting congruence + quantum SWAP")


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

47771dac82fff223ceb53e24f4c572173ac3885a674a7813a34d5311d3602098

Paper sections that cite this module

What this source index covers

The public registry includes 116 document views, 6,693 section records and 985 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.