## Dispersive estimates for Schrödinger operators: a survey.(English)Zbl 1143.35001

Bourgain, Jean (ed.) et al., Mathematical aspects of nonlinear dispersive equations. Lectures of the CMI/IAS workshop on mathematical aspects of nonlinear PDEs, Princeton, NJ, USA, 2004. Princeton, NJ: Princeton University Press (ISBN 978-0-691-12955-6/pbk; 978-0-691-12860-3/hbk). Annals of Mathematics Studies 163, 255-285 (2007).
This survey article is devoted to dispersive estimates for the Schrödinger flow
$e^{itH}P_c,\;H=-\Delta+ V\quad\text{on }\mathbb{R}^d,\;d\geq 1,$
here $$P_c$$ is the projection onto the continuous spectrum of $$H$$. The real-valued potential $$V= V(x)$$ satisfies some decay conditions at infinity of the form $$|V(x)|\leq C\langle x\rangle^{-\beta}$$, $$\beta> 0$$. The following estimates are of interest: dispersive estimates
$\sup_{t\neq 0}\,|t|^{d({1\over 2}-{1\over p})}\| e^{itH}P_cf\|_{L^q(\mathbb{R}^d)}\leq C\| f\|_{L^p(\mathbb{R}^d)}$
for all $$f\in L^1(\mathbb{R}^d)\cap L^2(\mathbb{R}^d)$$, $$p\in[1, 2]$$ and $${1\over p}+{1\over q}= 1$$; and Strichartz estimates $\| e^{itH}P_c f\|_{L^q_t(L^p_x)}\leq C\| f\|_{L^2(\mathbb{R}^d)}$ for all $${2\over q}+ {d\over p}= {d\over 2}$$, $$q\in (2,\infty]$$.
Content:
1. $$d\geq 3$$ (perturbation argument, Duhamels formula, spectral resolution, properties of resolvent, representation of resolvent, role of resonances);
2. $$d= 1$$ (weighted dispersive estimates);
3. $$d= 2$$ (zero as a regular point of the spectrum of $$-\Delta+ V$$);
4. time-dependent potentials (overview).
For the entire collection see [Zbl 1113.35005].

### MSC:

 35-02 Research exposition (monographs, survey articles) pertaining to partial differential equations 35B45 A priori estimates in context of PDEs 35Q40 PDEs in connection with quantum mechanics 35B34 Resonance in context of PDEs
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