TY - JOUR T1 - A new approach to a theorem of Eng AU - Arslan, Hasan PY - 2021 DA - December DO - 10.15672/hujms.900705 JF - Hacettepe Journal of Mathematics and Statistics PB - Hacettepe University WT - DergiPark SN - 2651-477X SP - 1679 EP - 1680 VL - 50 IS - 6 LA - en AB - The main aim of this work is to give a case-free algebraic proof for a theorem of Eng on the Poincaré polynomial of parabolic quotients of finite Coxeter groups evaluated at -1. KW - Coxeter groups KW - descent algebras KW - Poincaré polynomial KW - the longest element KW - $q=-1$ phenomenon CR - [1] D. Blessenohl, C. Hohlweg and M. Schocker, A symmetry of the descent algebra of a finite Coxeter group, Adv. Math. 193 (2), 416-437, 2005. CR - [2] C.W. Curtis and I. Reiner, Methods of Representation Theory with Applications to Finite Groups and Orders Vol. II, John Wiley and Sons, 1987. CR - [3] O. Eng, Quotients of Poincaré polynomials evaluated at -1, J. Algebraic Combin. 13 (1), 29-40, 2001. CR - [4] J.E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge Studies in Ad- vanced Mathematics 29, Cambridge University Press, 1990. CR - [5] V. Reiner, Note on a theorem of Eng, Ann. Comb. 6 (1), 117-118, 2002. CR - [6] V. Reiner, D. Stanton and D. White, The cyclic sieving phenomenon, J. Combin. Theory Ser. A 108 (1), 17-50, 2004. CR - [7] L. Solomon, A Mackey formula in the group ring of a Coxeter group, J. Algebra 41 (2), 255-264, 1976. UR - https://doi.org/10.15672/hujms.900705 L1 - https://dergipark.org.tr/en/download/article-file/1652929 ER -