Eulerian central limit theorems and Carlitz identities in positive elements of classical Weyl groups

Central Limit Theorems are known for the Eulerian statistic descent (or excedance) in the symmetric group ₙ. Recently, Fulman, Kim, Lee and Petersen gave a Central Limit Theorem for descent over the alternating group ₙ and also gave a Carlitz identity in ₙ using descents. In this paper, we give a Central Limit Theorem in ₙ involving excedances. We extend these to the positive elements in type B and type D Coxeter groups. Boroweic and Mlotkowski enumerated type B descents over ₙ, the type D Coxeter group and gave similar results. We refine their results for both the positive and negative part of ₙ. Our results are a consequence of signed enumeration over these subsets.