Published online by Cambridge University Press: 20 January 2009
Let , (n = 0, 1, ….) be the Laguerre, Hn(x) the Hermite polynomial. Let , be the space of all functions f(x) the pth powers of which are integrable over (a, b), with the norm
1. Banach, S.Theéorie des opérations linéaires (Warszawa, 1932), 58, théorème 7Google Scholar, Kaczmarz, S. and Steinhaus, H., Theorie der Orthogonalreihen (Warszawa-Lwów, 1935),Google Scholar [625] and [624]. There the theorem is proved for a finite interval, but it is also true for an infinite one, since the well known theorem [1.71] on moments is also valid for an infinite interval.
The theorem is also valid for complex-valued functions.
2. CfKaczmarz-Steinhaus, Google Scholar, I. c. This book contains a proof, page 280 et seq., but Kaczmarz's definition of a complete system is different from that used here. In order to apply their general theorem [874] on Laguerre polynomials, the condition n −1υ(nq)1/(nq) → 0, (n→ ∞, q = 1/p′), has to be replaced by
Then the theorem covers the completeness of in the cases 1 < p< ∞
3. Kober, H., Quart. J. of Math. (Oxford) 8 (1937), 186–99. Full details are given in the sixth section of the present paper.Google Scholar
4. Watson, G. N.Proc. London Math. Soc. (2), 35 (1933), 156–99.CrossRefGoogle ScholarBusbridge, I. W.Journal London Math. Soc. 9 (1934), 179–87.CrossRefGoogle Scholar
5. We can obtain the proof of this lemma by following the lines of the proof [483] given by Kaczmarz-Steinhaus. Let 0 < b < c, h(t) = ebt g(t) then (i) and (ii) imply g(t) ∈ £(0, ∞), h(t) ∈(0, ∞). The function
is regular for ; and for, |s| < b,
Therefore for, |s| < b,
Hence F(s) vanishes for , and by Lerch's theorem so also doges g(x).
6. CfKaczmarz-Steinhaus, , 1. c. [874] the proof covers the cases 1<p<∞ Here I outline another proof.Google Scholar
7. Kober, H., I. c.Google Scholar
8. Quart. J. of Math. (Oxford), 9 (1938), 196–8.Google Scholar
9. When J. ≦ 0 Cf. Szegö, G., Math. Zeitschrift, 25 (1926), 87–115.CrossRefGoogle Scholar
10. Kober, H., Annals of Math., 40 (1939), 549–59.CrossRefGoogle Scholar
11. Originally we deduced (6.7) for j≦0, from the properties of the operator with which we have already dealt in a former paper, Quart. J. of Math. (Oxford), 10 (1939), 45–59. The assertion stated on page 52, line 19–21, is untrue in general; when r = ½ it can be replaced by some results given in this paper. The operator F8 has also been dealt with in that paper.Google Scholar