On Fourier multipliers and comparison of differential operators
The talk consists of two parts.
1) Fourier multipliers and absolute convergence of Fourier integrals.
Based on the paper by Liflyand-Samko-Trigub "The Winer
algebra of absolutely convergent Fourier integrals: an overview",
Analysis and Math. Physics 2(2012), 1-68.
2) Comparison of linear differential operators with constant coefficients
by their norms in $L_p,$ $1\le p\le \infty$. In particular, three criteria
of comparison are obtained for functions on the circle, on the axis, and on
the half-axis, as well as one sharp inequality.