Chebyshev Approximation by γ-Polynomials

The approximation by sums of exponentials shares some of the properties of rational approximation. But there is an essential difference: the best approximation is not always unique. There may be more than one isolated solution, which means that phenomena arise which are not met in the linear theory. Fortunately, it is possible to establish explicit bounds for the number of solutions. In order to get them, the results for Haar embedded manifold (derived with methods of global analysis), are applied.