Fourier analysis provides a powerful framework for decomposing functions into sums or integrals of sinusoidal components, thereby enabling the study of frequency content in signals. In tandem, ...

Under the assumption that μ is a non-doubling measure on ℝd, the authors obtain the boundedness of commutators generated by Calderón-Zygmund operators or fractional integrals with Lipschitz functions ...

For 0 < s ≤ 1, we characterize those compact sets X with the property that each function harmonic in X̊ and satisfying a little o Lipschitz condition of order s is the limit in the Lipschitz norm of ...