Estimates for Eigenvalues of Poly-harmonic Operators
  In this paper, we study eigenvalues of the poly-Laplacian with arbitrary order on a bounded domain in an n-dimensional Euclidean space and obtain a lower bound for eigenvalues, which generalizes the results due to Cheng-Wei [5] and gives an improvement of results due to Cheng- Qi-Wei [3]. 
Guoxin Wei and Lingzhong Zeng
math.DG