Acta mathematica scientia,Series B ›› 2011, Vol. 31 ›› Issue (4): 1517-1534.doi: 10.1016/S0252-9602(11)60338-X

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Lp CONTINUITY OF HÖRMANDER SYMBOL OPERATORS OpSm0,0 AND NUMERICAL ALGORITHM

 YANG Qi-Xiang   

  1. School of Mathematics and Statistics, Wuhan University, Wuhan 430072, China
  • Received:2008-12-29 Online:2011-07-20 Published:2011-07-20
  • Supported by:

    Supported by the Doctoral programme foundation of National Education Ministry of China.

Abstract:

If we use Littlewood-Paley decomposition, there is no pseudo-orthogonality for H¨ormander symbol operators OpSm0,0, which is different to the case Smρ,δ (0 ≤δρ ≤ 1). In this paper, we use a special numerical algorithm based on wavelets to study the Lp
continuity of non infinite smooth operators OpSm0,0; in fact, we apply first special wavelets to symbol to get special basic operators, then we regroup all the special basic operators at given scale and prove that such scale operator’s continuity decreases very fast, we sum such scale operators and a symbol operator can be approached by very good compact operators. By correlation of basic operators, we get very exact pseudo-orthogonality and also L2L2 continuity for scale operators. By considering the influence region of scale operator, we get H1(= F0,21 ) → L1 continuity and L1 →BMO continuity. By interpolation theorem, we get also Lp(= F0,2p ) → Lp continuity for 1 < p < ∞. Our results are sharp for F0,2p →Lp continuity when 1 ≤ p ≤ 2, that is to say, we find out the exact order of derivations for
which the symbols can ensure the resulting operators to be bounded on these spaces.

Key words: H¨ormander symbol class, wavelet and numerical algorithm, basic operators and scale operators, approximation by compact operator and operator’s continuity

CLC Number: 

  • 42B20
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