2
votes
0answers
64 views

definition of the Fourier transform of function on the sphere

Let $f: S^{n-1}\longrightarrow R^n$ be even continuous function. What is the Fourier transform of $f$?
1
vote
1answer
34 views

Confusion of one definition in Fourier analysis

The symbol occurs on Page 22 of Bahouri's book Fourier analysis and nonlinear differential equations. As defined there, $$f(D)a:=\mathcal{F}^{-1}\{f\mathcal{F}a\}.$$ The question comes from the ...