Abstract
This survey paper is focused on a connection between the geometry of \(\mathop{\text{GL}}\nolimits _{d}\) and the arithmetic of \(\mathop{\text{GL}}\nolimits _{d-1}\) over global fields, for integers d ≥ 2. For d = 2 over \(\mathbb{Q}\), there is an explicit conjecture of the third author relating the geometry of modular curves and the arithmetic of cyclotomic fields, and it is proven in many instances by the work of the first two authors. The paper is divided into three parts: in the first, we explain the conjecture of the third author and the main result of the first two authors on it. In the second, we explain an analogous conjecture and result for d = 2 over \(\mathbb{F}_{q}(t)\). In the third, we pose questions for general d over the rationals, imaginary quadratic fields, and global function fields.
The original version of this chapter was revised. An erratum to this chapter can be found at DOI 10.1007/978-3-642-55245-8_17
An erratum to this chapter can be found at http://dx.doi.org/10.1007/978-3-642-55245-8_17
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
This is still not quite the right object unless we invert 2. In Sect. 4, we take the point of view that the right object is the relative homology of the quotient of the space X 1(Np r) by the action of complex conjugation.
- 2.
Actually, g α, β is a root of a unit, but the difficulties this causes are resolvable by passing to the projective limit and descending, so we ignore this for simplicity of presentation. We will be very careless about denominators in several places, omitting them where they occur for simplicity of the discussion that follows.
- 3.
There is one potentially confusing aspect: the action of \(\varLambda \hookrightarrow \mathfrak{h}\) on \(\mathfrak{S} \subset \varLambda [\![q]\!]\) is not given by multiplication of the coefficients of q-expansions by the element of Λ. It is instead this multiplication after first applying the inversion map λ ↦ λ ∗ on Λ that takes group elements to their inverses.
- 4.
It should actually be possible to allow either or both of p = 3 and \(p\mid \varphi (N)\) in what follows.
- 5.
The reader may wish to ignore the involutions in order to focus on the idea of the argument.
- 6.
Another, more usual, way to approach injectivity is to use \(I_{\theta } +\xi _{\theta }\mathfrak{h}_{\theta }\) in place of I θ until one recovers the equality of these ideals through a proof of the main conjecture, as in 2.5.7 below.
- 7.
In the projective limit, this gives another way of defining the isomorphism \(\mathfrak{h}_{\theta }/I_{\theta }\stackrel{\sim }{\rightarrow }\varLambda _{\theta }/(\xi _{\theta })\).
- 8.
To make sense of this, note that the tensor product in the sum is taken over \(\mathbb{Z}_{p}[\theta ]\).
- 9.
Actually, we know that the kernel coincides with (ξ θ ), but this weaker statement is enough.
- 10.
Note that q appears in this sentence as the order of the residue field of \(\mathcal{O}_{\infty }\).
- 11.
Actually, g α, β as we have described it is not well-defined until we take its q 2 − 1 power. The assumption that \(p \nmid (q^{2} - 1)\) is used to avoid this issue when we work with étale cohomology.
References
Ash, A.: Cohomology of congruence subgroups of \(\mathop{\text{SL}}\nolimits _{n}(\mathbb{Z})\). Math. Ann. 249, 55–73 (1980)
Busuioc, C.: The Steinberg symbol and special values of L-functions. Trans. Am. Math. Soc. 360, 5999–6015 (2008)
Carlitz, L.: A class of polynomials. Trans. Am. Math. Soc. 43, 167–182 (1938)
Cremona, J.: Hyperbolic tessellations, modular symbols, and elliptic curves over complex quadratic fields. Compos. Math. 51, 275–324 (1984)
Drinfeld, V.: Parabolic points and zeta functions of modular curves. Funkcional. Anal. i Priložen. 7, 83–84 (1973)
Drinfeld, V.: Elliptic modules. Mat. Sb. 94, 594–627, 656 (1974)
Emerton, E.: The Eisenstein ideal in Hida’s ordinary Hecke algebra. IMRN Int. Math. Res. Not. 1999 (15), 793–802 (1999)
Fukaya, T.: Coleman power series for K 2 and p-adic zeta functions of modular forms. In: Kazuya Kato’s fiftieth birthday. Doc. Math. Extra Vol., 387–442 (2003)
Fukaya, T., Kato, K.: On conjectures of Sharifi, 121pp (Preprint)
Gekeler, E.: A note on the finiteness of certain cuspidal divisor class groups. Isr. J. Math. 118, 357–368 (2000)
Goncharov, A.: Euler complexes and geometry of modular varieties. Geom. Funct. Anal. 17, 1872–1914 (2008)
Harder, G., Pink, R.: Modular konstruierte unverzweigte abelsche p-Erweiterungen von \(\mathbb{Q}(\zeta _{p})\) und die Struktur ihrer Galoisgruppen. Math. Nachr. 159, 83–99 (1992)
Hayes, D.: Explicit class field theory for rational function fields. Trans. Am. Math. Soc. 189, 77–91 (1974)
Hida, H.: Iwasawa modules attached to congruences of cusp forms. Ann. Sci. École Norm. Sup. 19, 231–273 (1986)
Kato, K.: p-adic Hodge theory and values of zeta functions of modular forms. In: Cohomologies p-adiques et Applications Arithmétique, III. Astérisque, vol. 295, pp. 117–290. Socit Mathmatique de France, Paris (2004)
Kondo, S.: Euler systems on Drinfeld modular curves and zeta values. Dissertation, University of Tokyo (2002)
Kondo, S.,Yasuda, S.: Zeta elements in the K-theory of Drinfeld modular varieties. Math. Ann. 354, 529–587 (2012)
Kurihara, M.: Ideal class groups of cyclotomic fields and modular forms of level 1. J. Number Theory 45, 281–294 (1993)
Manin, J.: Parabolic points and zeta-functions of modular curves. Math. USSR Izvsetija 6, 19–64 (1972)
Mazur, B., Wiles, A.: Class fields of abelian extensions of \(\mathbb{Q}\). Invent. Math. 76, 179–330 (1984)
McCallum, W., Sharifi, R.: A cup product in the Galois cohomology of number fields. Duke Math. J. 120, 269–310 (2003)
Ochiai, T.: On the two-variable Iwasawa main conjecture. Compos. Math. 142, 1157–1200 (2006)
Ohta, M.: On the p-adic Eichler-Shimura isomorphism for Λ-adic cusp forms. J. reine angew. Math. 463, 49–98 (1995)
Ohta, M.: Ordinary p-adic étale cohomology groups attached to towers of elliptic modular curves. II. Math. Ann. 318, 557–583 (2000)
Ohta, M.: Congruence modules related to Eisenstein series. Ann. Éc. Norm. Sup. 36, 225–269 (2003)
Pal, A.: The rigid analytical regulator and K 2 of Drinfeld modular curves. Publ. Res. Inst. Math. Sci. 46, 289–334 (2010)
Ribet, K.: A modular construction of unramified p-extensions of \(\mathbb{Q}(\mu _{p})\). Invent. Math. 34, 151–162 (1976)
Sharifi, R.: A reciprocity map and the two variable p-adic L-function. Ann. Math. 173, 251–300 (2011)
Tate, J.: Relations between K 2 and Galois cohomology. Invent. Math. 36, 257–274 (1976)
Teitelbaum, J.: Modular symbols for F q (T). Duke Math. J. 69, 271–295 (1992)
Wiles, A.: On ordinary λ-adic representations associated to modular forms. Invent. Math. 94, 529–573 (1988)
Acknowledgements
The work of the first two authors (resp., third author) was supported in part by the National Science Foundation under Grant Nos. DMS-1001729 (resp., DMS-0901526).
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2014 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Fukaya, T., Kato, K., Sharifi, R. (2014). Modular Symbols in Iwasawa Theory. In: Bouganis, T., Venjakob, O. (eds) Iwasawa Theory 2012. Contributions in Mathematical and Computational Sciences, vol 7. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-55245-8_5
Download citation
DOI: https://doi.org/10.1007/978-3-642-55245-8_5
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-55244-1
Online ISBN: 978-3-642-55245-8
eBook Packages: Mathematics and StatisticsMathematics and Statistics (R0)