An optimal uncertainty principle in twelve dimensions via modular forms
An optimal uncertainty principle in twelve dimensions via modular forms
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通过模块化形式的十二维最优不确定性原理
DOI:
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发表时间:
2017
影响因子:
3.1
通讯作者:
Felipe Gonçalves
中科院分区:
文献类型:
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作者:
Henry Cohn;Felipe Gonçalves
We prove an optimal bound in twelve dimensions for the uncertainty principle of Bourgain, Clozel, and Kahane. Suppose $$f :mathbb {R}^{12}
ightarrow mathbb {R}$$f:R12→R is an integrable function that is not identically zero. Normalize its Fourier transform $$widehat{f}$$f^ by $$widehat{f}(xi ) = int _{mathbb {R}^d} f(x)e^{-2pi i langle x, xi
angle }, dx$$f^(ξ)=∫Rdf(x)e-2πi⟨x,ξ⟩dx, and suppose $$widehat{f}$$f^ is real-valued and integrable. We show that if $$f(0) le 0$$f(0)≤0, $$widehat{f}(0) le 0$$f^(0)≤0, $$f(x) ge 0$$f(x)≥0 for $$|x| ge r_1$$|x|≥r1, and $$widehat{f}(xi ) ge 0$$f^(ξ)≥0 for $$|xi | ge r_2$$|ξ|≥r2, then $$r_1r_2 ge 2$$r1r2≥2, and this bound is sharp. The construction of a function attaining the bound is based on Viazovska’s modular form techniques, and its optimality follows from the existence of the Eisenstein series $$E_6$$E6. No sharp bound is known, or even conjectured, in any other dimension. We also develop a connection with the linear programming bound of Cohn and Elkies, which lets us generalize the sign pattern of f and $$widehat{f}$$f^ to develop a complementary uncertainty principle. This generalization unites the uncertainty principle with the linear programming bound as aspects of a broader theory.