%0 Journal Article %T Expression d'un facteur epsilon de paire par une formule intégrale %+ Institut de Mathématiques de Jussieu (IMJ) %A Beuzart-Plessis, Raphaël %Z 58p. %< avec comité de lecture %@ 0008-414X %J Canadian Journal of Mathematics %I University of Toronto Press %V 66 %N 5 %P 993-1049 %8 2014-10-01 %D 2014 %Z 1212.1082 %R 10.4153/CJM-2013-042-4 %K twisted groups %K epsilon factor %Z Mathematics [math]/Representation Theory [math.RT] %Z Mathematics [math]/Number Theory [math.NT]Journal articles %X Let $E/F$ be a quadratic extension of $p$-adic fields and let $d$, $m$ be nonnegative integers of distinct parities. Fix admissible irreducible tempered representations $\pi$ and $\sigma$ of $GL_d(E)$ and $GL_m(E)$ respectively. We assume that $\pi$ and $\sigma$ are conjugate-dual. That is to say $\pi\simeq \pi^{\vee,c}$ and $\sigma\simeq \sigma^{\vee,c}$) where $c$ is the non trivial $F$-automorphism of $E$. This implies, we can extend $\pi$ to an unitary representation $\tilde{\pi}$ of a nonconnected group $GL_d(E)\rtimes \{1,\theta\}$. Define $\tilde{\sigma}$ the same way. We state and prove an integral formula for $\epsilon(1/2,\pi\times \sigma,\psi_E)$ involving the characters of $\tilde{\pi}$ and $\tilde{\sigma}$. This formula is related to the local Gan-Gross-Prasad conjecture for unitary groups. %G French %2 https://hal.science/hal-00761080v2/document %2 https://hal.science/hal-00761080v2/file/articleeps-1.pdf %L hal-00761080 %U https://hal.science/hal-00761080 %~ UNIV-PARIS7 %~ UPMC %~ CNRS %~ IMJ %~ UPMC_POLE_1 %~ SORBONNE-UNIVERSITE %~ SU-SCIENCES %~ UNIV-PARIS %~ UP-SCIENCES %~ SU-TI %~ ALLIANCE-SU