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On L-packets and depth for SL2(K)
Sergio Mendes  1@  , Anne-Marie Aubert  2@  , Roger Plymen  3@  
1 : University Institute of Lisbon  (ISCTE-IUL)  -  Website
Avenida das Forças Armadas, 1649-026 Lisboa -  Portugal
2 : Institut de Mathématiques de Jussieu/ Paris Rive Gauche  (IMJ-PRG)
CNRS : UMR7586, Université Pierre et Marie Curie (UPMC) - Paris VI, Unirsité Denis Diderot
3 : University of Southampton  -  Website

Let G = SL2(K) with K a local function field of characteristic 2. We review the Artin-Schreier symbol for the field K, and show that this leads to a parametrization of certain L-packets in the smooth dual of G. The L-packets in the principal series are parametrized by quadratic extensions, and the supercuspidal L-packets of cardinality 4 are parametrized by biquadratic extensions. Each supercuspidal packet of cardinality 4 is accompanied by a singleton packet for SL1(D). We provide lower bounds for the depths of the irreducible constituents of all these L-packets for SL2(K) and its inner form SL1(D).


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