claimroutineinferred_dep

Global mixed paraboloid extension estimate

Paraboloid extension La→LbL^a\to L^b holds globally for b>pcb>p_c, b>(d+2)a′/db>(d+2)a'/d
lossless global extension for the Besov smoothing
Claim·§12 The paraboloid and Schr\"odinger evolution·inside corParaboloid extension and Schrödinger local smoothing

Statement (paper)

For d≥1d\ge1, pc=2(d+1)/dp_c=2(d+1)/d, 1<a≤∞1<a\le\infty, pc<b<∞p_c<b<\infty and b>(d+2)a′/db>(d+2)a'/d, the extension operator satisfies ∥Eg∥Lb(Rd+1)≲d,a,b∥g∥La(Bd)\|Eg\|_{L^b(\RR^{d+1})}\lesssim_{d,a,b}\|g\|_{L^a(B_d)}. In particular, E:Lpc(Bd)→Ls(Rd+1)E:L^{p_c}(B_d)\to L^s(\RR^{d+1}) for every s>pcs>p_c.

In plain English

For 1<a≤∞1<a\le\infty, pc<b<∞p_c<b<\infty and b>(d+2)a′/db>(d+2)a'/d, the paraboloid extension operator is bounded La(Bd)→Lb(Rd+1)L^a(B_d)\to L^b(\RR^{d+1}). In particular EE maps Lpc(Bd)L^{p_c}(B_d) into Ls(Rd+1)L^s(\RR^{d+1}) for every s>pcs>p_c.

Why it's here

The local logarithmic-loss bound at pcp_c from the previous claim is upgraded to a global, lossless bound by epsilon removal, using that the log loss can be traded for the room b>pcb>p_c and the range condition on (a,b)(a,b). The analogous sphere argument in the spherical restriction corollary guides this, and the resulting global bound feeds into the mixed-norm Besov local smoothing estimate for Schrödinger evolution.
Classified routine:
Follows from the preceding local log-loss bound via Tao's epsilon-removal lemma (Tao 1999), mirroring the paper's own argument for the sphere in cor-spherical-restriction; the resulting range is the classical Stein–Tomas/restriction-conjecture range for the paraboloid.

Sources

PaperOpen
Section
§12 The paraboloid and Schr\"odinger evolution
Page
—
Label
—
Line
sections/parabolic.tex:72
Leannot aligned

Phase 2 aligns this node to a Lean declaration.

Friction

  • info
    inferred_dep
    outline: "Global mixed paraboloid extension by epsilon removal" rests on claim-cor-parabolic-1