Published online by Cambridge University Press: 17 December 2020
This paper generalizes the Gan–Gross–Prasad (GGP) conjectures that were earlier formulated for tempered or more generally generic L-packets to Arthur packets, especially for the non-generic L-packets arising from Arthur parameters. The paper introduces the key notion of a relevant pair of Arthur parameters that governs the branching laws for  ${{\rm GL}}_n$ and all classical groups over both local fields and global fields. It plays a role for all the branching problems studied in Gan et al. [Symplectic local root numbers, central critical L-values and restriction problems in the representation theory of classical groups. Sur les conjectures de Gross et Prasad. I, Astérisque 346 (2012), 1–109] including Bessel models and Fourier–Jacobi models.
${{\rm GL}}_n$ and all classical groups over both local fields and global fields. It plays a role for all the branching problems studied in Gan et al. [Symplectic local root numbers, central critical L-values and restriction problems in the representation theory of classical groups. Sur les conjectures de Gross et Prasad. I, Astérisque 346 (2012), 1–109] including Bessel models and Fourier–Jacobi models.
WTG is partially supported by an MOE Tier 2 grant R146-000-233-112. DP thanks the Science and Engineering Research Board of the Department of Science and Technology, India for its support through the JC Bose National Fellowship of the Government of India, project number JBR/2020/000006. His work was also supported by a grant of the Government of the Russian Federation for the state support of scientific research carried out under the agreement 14.W03.31.0030 dated 15 February 2018.
 $n$), Math. Res. Lett. 25 (2018), 1695–1717.10.4310/MRL.2018.v25.n6.a1CrossRefGoogle Scholar
$n$), Math. Res. Lett. 25 (2018), 1695–1717.10.4310/MRL.2018.v25.n6.a1CrossRefGoogle Scholar ${{\rm GL}}(m,D)$, Ann. Inst. Fourier (Grenoble) 63 (2013), 2239–2266.CrossRefGoogle Scholar
${{\rm GL}}(m,D)$, Ann. Inst. Fourier (Grenoble) 63 (2013), 2239–2266.CrossRefGoogle Scholar $p$-adic groups, Ann. Sci. Éc. Norm. Supér. 10 (1977), 441–472.CrossRefGoogle Scholar
$p$-adic groups, Ann. Sci. Éc. Norm. Supér. 10 (1977), 441–472.CrossRefGoogle Scholar $({{\rm GL}}_{n+1}(F),{{\rm GL}}_n(F))$: projectivity and indecomposability, Preprint (2019), arXiv:1905.01668.Google Scholar
$({{\rm GL}}_{n+1}(F),{{\rm GL}}_n(F))$: projectivity and indecomposability, Preprint (2019), arXiv:1905.01668.Google Scholar ${\rm Mp}_{2n}$, Ann. of Math. (2) 188 (2018), 965–1016.Google Scholar
${\rm Mp}_{2n}$, Ann. of Math. (2) 188 (2018), 965–1016.Google Scholar ${\rm U}(3)$, Invent. Math. 105 (1991), 445–472.10.1007/BF01232276CrossRefGoogle Scholar
${\rm U}(3)$, Invent. Math. 105 (1991), 445–472.10.1007/BF01232276CrossRefGoogle Scholar ${{\rm GL}}_{2n}$ and
${{\rm GL}}_{2n}$ and  $ {{{\rm \tilde{S}p}}}_{2n}$, J. Amer. Math. Soc. 12 (1999), 849–907.CrossRefGoogle Scholar
$ {{{\rm \tilde{S}p}}}_{2n}$, J. Amer. Math. Soc. 12 (1999), 849–907.CrossRefGoogle Scholar ${{\rm GL}}_m$ to classical groups, Ann. of Math. (2) 150 (1999), 807–866.10.2307/121057CrossRefGoogle Scholar
${{\rm GL}}_m$ to classical groups, Ann. of Math. (2) 150 (1999), 807–866.10.2307/121057CrossRefGoogle Scholar ${{{\rm \tilde{S}p}}}_{2n}$, J. Inst. Math. Jussieu 1 (2002), 77–123.CrossRefGoogle Scholar
${{{\rm \tilde{S}p}}}_{2n}$, J. Inst. Math. Jussieu 1 (2002), 77–123.CrossRefGoogle Scholar ${\rm SO}_{n}$ when restricted to
${\rm SO}_{n}$ when restricted to  $\,{\rm SO}_{n-1}$, Canad. J. Math. 44 (1992), 974–1002.CrossRefGoogle Scholar
$\,{\rm SO}_{n-1}$, Canad. J. Math. 44 (1992), 974–1002.CrossRefGoogle Scholar $\,{\rm SO}_{2n+1}\times {\rm SO}_{2m}$, Canad. J. Math. 46 (1994), 930–950.CrossRefGoogle Scholar
$\,{\rm SO}_{2n+1}\times {\rm SO}_{2m}$, Canad. J. Math. 46 (1994), 930–950.CrossRefGoogle Scholar $\theta _{{10}}$ Arthur parameter and Gross–Prasad conjecture, J. Number Theory 153 (2015), 372–426.CrossRefGoogle Scholar
$\theta _{{10}}$ Arthur parameter and Gross–Prasad conjecture, J. Number Theory 153 (2015), 372–426.CrossRefGoogle Scholar ${\rm U}(3)\times {\rm U}(2)$: the non-generic case, J. Number Theory 165 (2016), 324–354.CrossRefGoogle Scholar
${\rm U}(3)\times {\rm U}(2)$: the non-generic case, J. Number Theory 165 (2016), 324–354.CrossRefGoogle Scholar ${\rm U}(3)\times {\rm U}(3)$: the nongeneric case, Pacific J. Math. 286 (2017), 69–89.CrossRefGoogle Scholar
${\rm U}(3)\times {\rm U}(3)$: the nongeneric case, Pacific J. Math. 286 (2017), 69–89.CrossRefGoogle Scholar $({{\rm GL}}_{n+1} \times {{\rm GL}}_n, {{\rm GL}}_n)$, Compos. Math. 151 (2015), 665–712.CrossRefGoogle Scholar
$({{\rm GL}}_{n+1} \times {{\rm GL}}_n, {{\rm GL}}_n)$, Compos. Math. 151 (2015), 665–712.CrossRefGoogle Scholar $({{\rm Sp}}(n),O(V))$, J. Reine Angew. Math. 567 (2004), 99–150.Google Scholar
$({{\rm Sp}}(n),O(V))$, J. Reine Angew. Math. 567 (2004), 99–150.Google Scholar $({{\rm Sp}}(n),O(V))$, Israel J. Math. 164 (2008), 87–124.CrossRefGoogle Scholar
$({{\rm Sp}}(n),O(V))$, Israel J. Math. 164 (2008), 87–124.CrossRefGoogle Scholar $({{\rm Sp}}_{2n},O(V))$, Canad. J. Math. 60 (2008), 1306–1335.CrossRefGoogle Scholar
$({{\rm Sp}}_{2n},O(V))$, Canad. J. Math. 60 (2008), 1306–1335.CrossRefGoogle Scholar ${{\rm GL}}_{2n}$ distinguished by the symplectic group, J. Number Theory 125 (2007), 344–355.CrossRefGoogle Scholar
${{\rm GL}}_{2n}$ distinguished by the symplectic group, J. Number Theory 125 (2007), 344–355.CrossRefGoogle Scholar ${{\rm GL}}_2$ over a local field, Amer. J. Math. 114 (1992), 1317–1363.CrossRefGoogle Scholar
${{\rm GL}}_2$ over a local field, Amer. J. Math. 114 (1992), 1317–1363.CrossRefGoogle Scholar ${{\rm GL}}(n)$, Represent. Theory 9 (2005), 268–286.CrossRefGoogle Scholar
${{\rm GL}}(n)$, Represent. Theory 9 (2005), 268–286.CrossRefGoogle Scholar ${{\rm GL}}_{n}$ distinguished by
${{\rm GL}}_{n}$ distinguished by  ${{\rm GL}}_{n-1}$ over a
${{\rm GL}}_{n-1}$ over a  $p$-adic field, Israel J. Math. 194 (2013), 1–44.CrossRefGoogle Scholar
$p$-adic field, Israel J. Math. 194 (2013), 1–44.CrossRefGoogle Scholar