Representation of Fourier Integrals as Sums. Iip

نویسنده

  • R. J. DUFFIN
چکیده

provided an = sin (wn/2) and k(x) =sin (irx/2). Weinberger [8] treated the case when the coefficients a„ form a periodic sequence; that is an+q = a„ for some integer q. Making use of the character theory of Dirichlet 7-functions, he found the conditions on the a„ so that (3) holds with the kernel (2/q112) cos (2irx/q) or the kernel (2/q112) sin (2irx/q). (These kernels give self-reciprocal transforms for any value of q.) Weinberger's proofs hold under essentially the same conditions on (p as given in I. Boas [l ] made use of Poisson's summation formula to obtain representation formulae of the type (1) and (2) together with certain generalizations. In this connection it is of interest to note that the following Poisson summation formula

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Speed of convergence of two-dimensional Fourier integrals

1. Introduction Recently [2,3] we found necessary and sufficient conditions for the convergence at a preassigned point of the spherical partial sums of the Fourier integral in a class of piece-wise smooth functions in Euclidean space. These yield elementary examples of divergent Fourier integrals in three dimensions and higher. Meanwhile, several years ago Gottlieb and Orsag[1] observed that in...

متن کامل

Harmonic analysis on spheres, I

Harmonic analysis on the line is the theory of Fourier transforms, more complicated than Fourier series, due to the line’s non-compactness. On R the exponential functions, while still eigenfunctions for d dx and still giving group homomorphisms, are no longer in L(R). Entangled with this point is the fact that Fourier inversion expresses functions as integrals of exponential functions, not as s...

متن کامل

Fourier Series Formalization in ACL2(r)

We formalize some basic properties of Fourier series in the logic of ACL2(r), which is a variant of ACL2 that supports reasoning about the real and complex numbers by way of non-standard analysis. More specifically, we extend a framework for formally evaluating definite integrals of real-valued, continuous functions using the Second Fundamental Theorem of Calculus. Our extended framework is als...

متن کامل

Combinatorics of binomial decompositions of the simplest Hodge integrals

We reduce the calculation of the simplest Hodge integrals to some sums over decorated trees. Since Hodge integrals are already calculated, this gives a proof of a rather interesting combinatorial theorem and a new representation of Bernoulli numbers.

متن کامل

Integral representation of the Fermi distribution and its applications in electronic-structure calculations.

Many important quantities in electronic structure calculations are given as sums or integrals involving the Fermi distribution. These integrals usually cannot be solved analytically. Many methods have therefore been developed to evaluate these integrals approximately, the best known being the Sommerfeld expansion' and the Matsubara expansion. Here we derive an integral representation which will...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2010