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THE FLAT EXTENSION OF NONSINGULAR EMBRY MOMENT MATRICES E(3)

  • Li, Chunji (Department of Mathematics Northeastern University) ;
  • Liang, Hongkai (Department of Mathematics Northeastern University)
  • Received : 2018.10.17
  • Accepted : 2019.03.11
  • Published : 2020.01.31

Abstract

Let γ(n) ≡ {γij} (0 ≤ i+j ≤ 2n, |i-j| ≤ n) be a sequence in the complex number set ℂ and let E (n) be the Embry truncated moment matrices corresponding from γ(n). For an odd number n, it is known that γ(n) has a rank E (n)-atomic representing measure if and only if E(n) ≥ 0 and E(n) admits a flat extension E(n + 1). In this paper we suggest a related problem: if E(n) is positive and nonsingular, does E(n) have a flat extension E(n + 1)? and give a negative answer in the case of E(3). And we obtain some necessary conditions for positive and nonsingular matrix E (3), and also its sufficient conditions.

Keywords

Acknowledgement

The authors would like to thank the referee for the helpful suggestions

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