A generalized Poincaré inequality for Gaussian measures
A generalized Poincaré inequality for Gaussian measures
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DOI:
10.1090/s0002-9939-1989-0954373-7
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发表时间:
1989-02
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影响因子:
--
通讯作者:
W. Beckner
中科院分区:
文献类型:
--
作者:
W. Beckner
New inequalities are obtained which interpolate in a sharp way between the Poincaré inequality and the logarithmic Sobolev inequality for both Gaussian measure and spherical surface measure. The classical Poincaré inequality provides an estimate for the first nontrivial eigenvalue of a positive self-adjoint operator that annihilates constants. For the Gaussian measure dp = T\k(2n)~{'2e~({l2)Xkdxk and the generator of the Ornstein-Uhlenbeck process N = -A + x • V, the Poincaré inequality is simply the estimate (1) ¡\f\2dp-[j fdp) <j\Vf\2dp. This is an old inequality in the folklore of Hermite polynomials and probably was known in one dimension to both mathematicians and physicists in the 1930's in relation to eigenvalue problems ([9], [10]). It has been a useful tool in diverse subjects including partial differential equations [7] and statistics [4]. The purpose here is to note a generalized form of this estimate which interpolates in a sharp way between the Poincaré inequality and the logarithmic Sobolev inequality for Gaussian measures obtained by Gross [5]. Theorem 1. For f e L2(dp), 1 < p < 2 and e~' = sjp 1, (2) J l/l2 dp J \e~tNf\2 dp<(2-p)j |V/l2 dp and (3) j l/l2 dp (/ l/l" dp) " < (2 p) j |V/l2 dp. Such estimates are independent of dimension so one can regard the Gaussian measure space as infinite dimensional. The relation between these two Received by the editors August 1, 1988. 1980 Mathematics Subject Classification (1985 Revision). Primary 42B99; Secondary 60D05. This work was partially supported by the National Science Foundation. © 1989 American Mathematical Society 0002-9939/89 $1.00+ $.25 per page