This short note presents the Lambert W(x) function and its possible application in the framework of physics related to the Pierre Auger Observatory. The actual numerical implementation in C++ consists of Halley’s and Fritsch’s iteration with branch-point expansion, asymptotic series and rational fits as initial approximations. ar X iv :1 00 3. 16 28 v1 [ cs .M S] 8 M ar 2 01 0

We rewrite the Bagger-Lambert action for any Lie 3-algebra as a standard ChernSimons action coupled to matter. We use this action to compute self-energies and vertex corrections at one-loop order. Non-renormalization of the coupling constant comes out as a direct consequence of the Lie 3-algebra structure underlying the Lie algebra. [email protected]

The Lambert W(x) function and its possible applications in physics are presented. The actual numerical implementation in C++ consists of Halley’s and Fritsch’s iterations with initial approximations based on branch-point expansion, asymptotic series, rational fits, and continued-logarithm recursion.