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Lieb-Thirring Inequality


A Lieb-Thirring inequality bounds a sum of powers of the negative eigenvalues of a Schrödinger operator by an integral of its potential (Lieb and Thirring 1976). In one dimension, write H=-d^2/dx^2-W(x) on L^2(R) with W>=0. For gamma>=1/2, the inequality has the form

 sum_(E_j<0)|E_j|^gamma<=L_(gamma,1)intRW(x)^(gamma+1/2)dx,

where the negative eigenvalues are counted with multiplicity. The optimal constant is the least L_(gamma,1) that works for every admissible potential. The semiclassical value is

 L_(gamma,1)^(cl)=(Gamma(gamma+1))/(2sqrt(pi)Gamma(gamma+3/2)),

where Gamma is the gamma function.


See also

Eigenvalue, Gamma Function, Hermitian Matrix, Positive Semidefinite Matrix, Schrödinger Operator

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References

Lieb, E. H. and Thirring, W. E. "Inequalities for the Moments of the Eigenvalues of the Schrödinger Hamiltonian and Their Relation to Sobolev Inequalities." In Studies in Mathematical Physics: Essays in Honor of Valentine Bargmann (Ed. E. H. Lieb, B. Simon, and A. S. Wightman). Princeton, NJ: Princeton University Press, pp. 269-303, 1976.

Cite this as:

Weisstein, Eric W. "Lieb-Thirring Inequality." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Lieb-ThirringInequality.html

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