Pointwise convergence approximate identities of dilated radially decreasing kernels

Pointwise Kernels of Schwartz Distributions

We show that Schwartz distributions have kernels in the class of the pointwise nonstandard functions. The main purpose of this note is to show that every Schwartz distribution T G 3' has a kernel /: *Rd —> *C in the class of the pointwise nonstandard functions in the sense that (1) (T,p)= [ f(xy<p(x)dx for all <p G 3, where *<p is the nonstandard extension of (p. Recall that, in general, the Sc...

Pointwise Convergence of Trigonometric Series

We establish two results in the pointwise convergence problem of a trigonometric series [An] £ cne inl with lim Hm £ I bTck | = 0 |n|< -x. * Jn-»oo \k\-n for some nonnegative integer m. These results not only generalize Hardy's theorem, the Jordan test theorem and Fatou's theorem, but also complement the results on pointwise convergence of those Fourier series associated with known 1}-convergen...

Pointwise convergence of Fourier series

In the early 19 century, J. Fourier was an impassioned advocate of the use of such sums, of course writing sines and cosines rather than complex exponentials. Euler, the Bernouillis, and others had used such sums in similar fashions and for similar ends, but Fourier made a claim extravagant for the time, namely that all functions could be expressed in such terms. Unfortunately, in those days th...

Nonparametric deconvolution for decreasing kernels

A selection of these reports is available in PostScript form at the Faculty's anonymous ftp-Abstract A new nonparametric estimation procedure is introduced for a class of deconvolution problems where the convolution kernel is decreasing on 0; 1). The estimator is shown to be consistent and its cube root asymptotic distribution theory is established.

Sharp Pointwise Estimates on Heat Kernels