claimroutineinferred_dep

Mixed-norm Besov local smoothing for Schrödinger

Gives mixed bound LxpLtrL^p_xL^r_t from Bp,psB^s_{p,p} with s=d(1−2/p)−2/rs=d(1-2/p)-2/r
exact-order Schrödinger smoothing of the corollary
Claim·§12 The paraboloid and Schr\"odinger evolution·inside corParaboloid extension and Schrödinger local smoothing

Statement (paper)

Let pc<p<∞p_c<p<\infty and p≤r≤∞p\le r\le\infty, and let s=d(1−2/p)−2/rs=d(1-2/p)-2/r. Then for every Schwartz ff, ∥eitΔf∥Lp(Rd;Lr(I))≲d,p,r,I∥f∥Bp,ps(Rd)≲d,p,s∥(1−Δ)s/2f∥p\|e^{it\Delta}f\|_{L^p(\RR^d;L^r(I))}\lesssim_{d,p,r,I}\|f\|_{B^s_{p,p}(\RR^d)}\lesssim_{d,p,s}\|(1-\Delta)^{s/2}f\|_p, where the first inequality follows from with b=ab=a for some pc<a<pp_c<a<p, and the second from spatial Littlewood--Paley theory and ∥⋅∥ℓp≤∥⋅∥ℓ2\|\cdot\|_{\ell^p}\le\|\cdot\|_{\ell^2} for p>2p>2.

In plain English

For pc<p<∞p_c<p<\infty, p≤r≤∞p\le r\le\infty and s=d(1−2/p)−2/rs=d(1-2/p)-2/r, every Schwartz ff satisfies ∥eitΔf∥Lp(Rd;Lr(I))≲∥f∥Bp,ps≲∥(1−Δ)s/2f∥p\|e^{it\Delta}f\|_{L^p(\RR^d;L^r(I))}\lesssim\|f\|_{B^s_{p,p}}\lesssim\|(1-\Delta)^{s/2}f\|_p, with II a compact interval.

Why it's here

This is the final, exact-order Schrödinger local smoothing statement of the corollary, covering the spacetime (r=pr=p) and maximal (r=∞r=\infty) cases. The Besov bound comes from the global mixed extension estimate with b=ab=a for some pc<a<pp_c<a<p, applied to the frequency-localized pieces. The Sobolev bound follows from spatial Littlewood–Paley theory together with ℓp⊂ℓ2\ell^p\subset\ell^2 for p>2p>2.
Classified routine:
Follows from the preceding global paraboloid extension estimate by rescaling frequency-localized pieces, plus Littlewood–Paley theory and the embedding ℓ2⊂ℓp\ell^2\subset\ell^p; this is the standard passage from restriction/extension bounds to Schrödinger local smoothing (as in Rogers' work relating restriction to Schrödinger smoothing).

Uses

Used by

Nothing in the paper

Sources

PaperOpen
Section
§12 The paraboloid and Schr\"odinger evolution
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sections/parabolic.tex:131
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Friction

  • info
    inferred_dep
    outline: "Mixed-norm Besov local smoothing" rests on claim-cor-parabolic-2