Research proof index

The centered representative valMinAbs has the least absolute value among all integer representatives of a residue class.

ℓ∞ → ℓ₂² bridge (vector): ‖v‖₂² ≤ cols · (deg φ · ‖v‖∞²).

The ℓ∞ norm of a flattened block vector is bounded by γ as soon as every block is: the ℓ∞ norm of flattenBlocks is the supremum of the per-block ℓ∞ norms.

Coefficient of the basis element: v_j has coefficient [s = j]·(2 if j=0 else 1) at the position (d/2k)·s. The two basis exponents of v_j are (d/2k)·j (degree < d/2) and its conjugate (degree > d/2); only the former can equal (d/2k)·s < d/2, except at j=0 where the conjugate coincides (giving the doubling).

Full coefficient formula for the basis element v_j. For every position p < d, the p-th coefficient of v_j = X^{(d/2k)·j} + σ_{-1}(X^{(d/2k)·j}) is: 2 at p = 0 when j = 0; otherwise +1 at p = (d/2k)·j, -1 at the complementary position p = d - (d/2k)·j, and 0 elsewhere. This extends vElt_coeff (which only covers the positions `...

For i < 2^α (below the modulus degree), X^i is already reduced, so its j-th coefficient is the Kronecker delta [j = i].