Abstract
A local Riemann–Hilbert correspondence for tame meromorphic connections on a curve compatible with a parahoric level structure will be established. Special cases include logarithmic connections on G-bundles and on parabolic G-bundles. The corresponding Betti data involves pairs (M, P) consisting of the local monodromy M ∈ G and a (weighted) parabolic subgroup P ⊂ G such that M ∈ P, as in the multiplicative Brieskorn–Grothendieck–Springer resolution (extended to the parabolic case). The natural quasi-Hamiltonian structures that arise on such spaces of enriched monodromy data will also be constructed.
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A. Alekseev, A. Malkin, E. Meinrenken, Lie group valued moment maps, J. Differential Geom. 48 (1998), no. 3, 445–495, math.DG/9707021.
D. G. Babbitt, V. S. Varadarajan, Formal reduction theory of meromorphic differential equations: a group theoretic view, Pacific J. Math. 109 (1983), no. 1, 1–80.
V. Balaji, I. Biswas, D. S. Nagaraj, Ramified G-bundles as parabolic bundles, J. Ramanujan Math. Soc. 18 (2003), no. 2, 123–138.
O. Biquard, Sur les équations de Nahm et la structure de Poisson des algèbres de Lie semi-simples complexes, Math. Ann. 304 (1996), no. 2, 253–276.
O. Biquard, P. P. Boalch, Wild non-abelian Hodge theory on curves, Compositio Math. 140 (2004), no. 1, 179–204.
P. P. Boalch, Symplectic manifolds and isomonodromic deformations, Adv. Math. 163 (2001), 137–205.
P. P. Boalch, G-bundles, isomonodromy and quantum Weyl groups, Int. Math. Res. Not. IMRN (2002), no. 22, 1129–1166.
P. P. Boalch, Quasi-Hamiltonian geometry of meromorphic connections, Duke Math. J. 139 (2007), no. 2, 369–405, math.DG/0203161.
P. P. Boalch, Through the analytic halo: Fission via irregular singularities, Ann. Inst. Fourier (Grenoble) 59 (2009), no. 7, 2669–2684.
A. A. Bolibruch, On isomonodromic deformations of Fuchsian systems, J. Dyn. Control Syst. 3 (1997), no. 4, 589–604.
A. Borel, Linear Algebraic Groups, 2nd ed., Springer-Verlag, New York, 1991.
F. Bruhat, J. Tits, Groupes réductifs sur un corps local, Inst. Hautes Études Sci. Publ. Math. (1972), no. 41, 5–251.
P. Deligne, Équations Différentielles à Points Singuliers Réguliers, Lecture Notes in Mathematics, Vol. 163, Springer-Verlag, Berlin, 1970.
S. Evens, J.-H. Lu, Poisson geometry of the Grothendieck resolution of a complex semisimple group, Mosc. Math. J. 7 (2007), no. 4, 613–642.
S. Gukov, E. Witten, Gauge theory, ramification, and the geometric Langlands program (2006), arXiv.org:hep-th/0612073.
S. Gukov, E. Witten, Rigid surface operators (2008), arXiv.org:hep-th/0804.1561.
N. M. Katz, On the calculation of some differential Galois groups, Invent. Math. 87 (1987), no. 1, 13–61.
D. Kazhdan, G. Lusztig, Fixed point varieties on affine flag manifolds, Israel J. Math. 62 (1988), no. 2, 129–168.
A. H. M. Levelt, Hypergeometric functions, II, Indag. Math. 23 (1961), 373–385.
B. Malgrange, Sur les deformations isomonodromiques, I, Singularites regulieres, in: Séminaire E.N.S. Mathématique et Physique (Boston) (L. Boutet de Monvel, A. Douady, J.-L. Verdier, eds.), Progress in Mathematics, Vol. 37, Birkhäuser, Boston, 1983, pp. 401–426.
D. Mumford, J. Fogarty, F. Kirwan, Geometric Invariant Theory, 3rd ed., Springer-Verlag, Berlin, 1994.
G. Pappas, M. Rapoport, Twisted loop groups and their affine flag varieties, with an appendix by T. Haines and M. Rapoport, Adv. Math. 219 (2008), no. 1, 118–198.
C. Sabbah, Harmonic metrics and connections with irregular singularities, Ann. Inst. Fourier (Grenoble) 49 (1999), no. 4, 1265–1291.
C. S. Seshadri, Slides for talk entitled “Some Remarks on Parabolic Structures” at Ramanan’s conference (Miraores de la Sierra, Spain, 2008), www.mat.csic.es/webpages/moduli2008/ramanan/slides/seshadri.pdf.
C. T. Simpson, Harmonic bundles on noncompact curves, J. Amer. Math. Soc. 3 (1990), 713–770.
C. Teleman, C. Woodward, Parabolic bundles, products of conjugacy classes, and Gromov–Witten invariants, Ann. Inst. Fourier (Grenoble) 53 (2003), no. 3, 713–748.
D. Yamakawa, Geometry of multiplicative preprojective algebra, Int. Math. Res. Pap. IMRP (2008), Art. ID rpn008, 77 pp.
Z. Yun, Global Springer theory, to appear (cf. math/0904.3371).
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Boalch, P.P. Riemann–Hilbert for tame complex parahoric connections. Transformation Groups 16, 27–50 (2011). https://doi.org/10.1007/s00031-011-9121-1
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DOI: https://doi.org/10.1007/s00031-011-9121-1