On the Bloch-Kato conjecture for GSp(4)
Pith reviewed 2026-05-24 14:42 UTC · model grok-4.3
The pith
An explicit reciprocity law holds for the Euler system attached to the spin motive of a genus 2 Siegel modular form
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
We prove an explicit reciprocity law for the Euler system attached to the spin motive of a genus 2 Siegel modular form. As consequences, we obtain one inclusion of the Iwasawa Main Conjecture for such motives, and the Bloch--Kato conjecture in analytic rank 0 for their critical twists.
What carries the argument
The Euler system attached to the spin motive of the genus 2 Siegel modular form, which encodes the local and global data needed to formulate and verify the reciprocity relation.
If this is right
- One inclusion of the Iwasawa Main Conjecture holds for the spin motives of genus 2 Siegel modular forms.
- The Bloch-Kato conjecture holds in analytic rank zero for critical twists of these motives.
- The reciprocity law equates the image of the Euler system with the image of the p-adic L-function in the appropriate cohomology group.
Where Pith is reading between the lines
- The same reciprocity technique may apply to other motives attached to automorphic forms on GSp(4) or related groups once suitable Euler systems are constructed.
- It suggests that verifying local compatibility conditions for Euler systems can serve as a route to Bloch-Kato type results beyond the cases treated here.
- Obtaining the opposite inclusion in the Iwasawa main conjecture would require an independent construction that bounds the Selmer group from above.
Load-bearing premise
The spin motive of the genus 2 Siegel modular form admits a well-defined Euler system whose local properties are compatible with the reciprocity law being proved.
What would settle it
A concrete genus 2 Siegel modular form for which the Euler system classes fail to map under the reciprocity map to the expected elements in the Selmer group or p-adic L-function would disprove the claim.
read the original abstract
We prove an explicit reciprocity law for the Euler system attached to the spin motive of a genus 2 Siegel modular form. As consequences, we obtain one inclusion of the Iwasawa Main Conjecture for such motives, and the Bloch--Kato conjecture in analytic rank 0 for their critical twists.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript proves an explicit reciprocity law for the Euler system attached to the spin motive of a genus 2 Siegel modular form. As consequences, it obtains one inclusion of the Iwasawa Main Conjecture for such motives and the Bloch-Kato conjecture in analytic rank 0 for their critical twists.
Significance. If the central claim holds, the result would supply a concrete instance of an explicit reciprocity law in the GSp(4) setting, yielding partial progress on the Iwasawa main conjecture and Bloch-Kato for spin motives of Siegel forms. The explicit character of the reciprocity (relating Euler-system classes to a p-adic L-function or its derivative) is a potential strength, provided the Euler-system construction and local compatibility are fully rigorous.
minor comments (1)
- The abstract states the main theorem and consequences but supplies no section references, equation numbers, or outline of the Euler-system construction, norm relations, or local computations at bad primes; this prevents verification of load-bearing steps from the provided text.
Simulated Author's Rebuttal
We thank the referee for their summary of the manuscript and for acknowledging the potential significance of an explicit reciprocity law in the GSp(4) setting. No specific major comments were listed in the report, so we provide no point-by-point responses below. We remain available to clarify any aspects of the Euler system construction, local compatibility, or the resulting applications to the Iwasawa main conjecture and Bloch-Kato conjecture.
Circularity Check
No significant circularity detected
full rationale
The paper states it proves an explicit reciprocity law for a pre-existing Euler system attached to the spin motive, then derives one inclusion of the Iwasawa main conjecture and the Bloch-Kato conjecture in analytic rank zero. No equations, definitions, or steps in the provided abstract or description reduce a claimed prediction or theorem to a fitted parameter, self-citation chain, or input by construction. The central claim rests on constructing or verifying the reciprocity map itself rather than renaming or tautologically re-deriving its inputs. This is the normal case of an independent proof in Iwasawa theory.
Axiom & Free-Parameter Ledger
Reference graph
Works this paper leans on
-
[1]
F. Andreatta, A. Iovita, and G. Stevens, Overconvergent E ichler- S himura isomorphisms , J. Inst. Math. Jussieu 14 (2015), no. 2, 221--274. 3315057
work page 2015
-
[2]
K. Bannai and G. Kings, p -adic elliptic polylogarithm, p -adic E isenstein series and K atz measure , Amer. J. Math. 132 (2010), no. 6, 1609--1654. 2766179
work page 2010
-
[3]
A. A. Be linson, http://dx.doi.org/10.1090/conm/055.1/862627 Higher regulators of modular curves , Applications of algebraic K -theory to algebraic geometry and number theory, ( B oulder, C olo., 1983), Contemp. Math., vol. 55, Amer. Math. Soc., 1986, pp. 1--34. 862627
-
[4]
P. Berthelot, http://dx.doi.org/10.1007/s002220050143 Finitude et puret\' e cohomologique en cohomologie rigide , Invent. Math. 128 (1997), no. 2, 329--377, With an appendix in English by Aise Johan de Jong. 1440308
-
[5]
A. Besser, http://dx.doi.org/10.1007/s11856-011-0188-0 On the syntomic regulator for K_1 of a surface , Israel J. Math. 190 (2012), no. 1, 29--66. 2956231
-
[6]
A. Besser, D. Loeffler, and S. L. Zerbes, http://dx.doi.org/10.1007/s40316-015-0041-7 Finite polynomial cohomology for general varieties , Ann. Math. Qu\' e . 40 (2016), no. 1, 203--220. 3512529
-
[7]
F. Brown and C. Dupont, http://arxiv.org/abs/1810.07682 Single-valued integration and superstring amplitudes in genus zero , preprint, 2018, arXiv:1810.07682
-
[8]
D \'e glise, Around the G ysin triangle
F. D \'e glise, Around the G ysin triangle. II , Doc. Math. 13 (2008), 613--675. 2466188
work page 2008
-
[9]
P. Deligne and L. Illusie, http://dx.doi.org/10.1007/BF01389078 Rel\`evements modulo p^2 et d\' e composition du complexe de de R ham , Invent. Math. 89 (1987), no. 2, 247--270. 894379
-
[10]
M. Dimitrov, F. Januszewski, and A. Raghuram, http://arxiv.org/abs/1802.10064 L -functions of GL (2n) : p -adic properties and non-vanishing of twists , preprint, 2018, arXiv:1802.10064
-
[11]
V. Ertl and K. Yamada, http://arxiv.org/abs/1805.04974v1 Comparison between rigid syntomic and crystalline syntomic cohomology for strictly semistable log schemes with boundary , preprint, 2018, arXiv:1805.04974v1
-
[12]
, Poincare duality for H yodo-- K ato cohomology , preprint, 2019
work page 2019
-
[13]
G. Faltings, Crystalline cohomology and p -adic G alois-representations , Algebraic analysis, geometry, and number theory ( B altimore, MD , 1988), Johns Hopkins Univ. Press, 1989, pp. 25--80. 1463696
work page 1988
-
[14]
G. Faltings and C.-L. Chai, http://dx.doi.org/10.1007/978-3-662-02632-8 Degeneration of abelian varieties , Ergebnisse der Mathematik und ihrer Grenzgebiete (3), vol. 22, Springer, 1990. 1083353
-
[15]
A. Genestier and J. Tilouine, Syst\`emes de T aylor- W iles pour GSp _4 , Ast \'e risque 302 (2005), 177--290, Formes automorphes. II. Le cas du groupe GSp (4) . 2234862
work page 2005
-
[16]
o nne, de R ham- K ohomologie in der rigiden A nalysis , Ph.D. thesis, Universit\
E. Grosse-Kl \"o nne, de R ham- K ohomologie in der rigiden A nalysis , Ph.D. thesis, Universit\"at M\"unster, 1998
work page 1998
-
[17]
, http://dx.doi.org/10.1515/crll.2000.018 Rigid analytic spaces with overconvergent structure sheaf , J. Reine Angew. Math. 519 (2000), 73--95. 1739729
-
[18]
, http://dx.doi.org/10.1215/S0012-7094-02-11312-X Finiteness of de R ham cohomology in rigid analysis , Duke Math. J. 113 (2002), no. 1, 57--91. 1905392
-
[19]
E. Grosse-Kl\" o nne, https://0-doi-org.pugwash.lib.warwick.ac.uk/10.1090/S0002-9947-07-04138-4 The C ech filtration and monodromy in log crystalline cohomology , Trans. Amer. Math. Soc. 359 (2007), no. 6, 2945--2972. 2286064
-
[20]
M. Harris, Occult period invariants and critical values of the degree four L -function of GSp (4) , Contributions to automorphic forms, geometry, and number theory (in honour of J. Shalika), Johns Hopkins Univ. Press, 2004, pp. 331--354. 2058613
work page 2004
-
[21]
G. Kings, D. Loeffler, and S. L. Zerbes, http://dx.doi.org/10.4310/CJM.2017.v5.n1.a1 R ankin-- E isenstein classes and explicit reciprocity laws , Cambridge J. Math. 5 (2017), no. 1, 1--122. 3637653
-
[22]
, https://preprint.press.jhu.edu/ajm/issue/volume-142-number-1-february-2020 R ankin-- E isenstein classes for modular forms , Amer. J. Math. 142 (2020), no. 1
work page 2020
-
[23]
Lan, Integral models of toroidal compactifications with projective cone decompositions, Int
K.-W. Lan, Integral models of toroidal compactifications with projective cone decompositions, Int. Math. Res. Not. 2017 (2017), no. 11, 3237--3280. 3693649
work page 2017
-
[24]
K.-W. Lan and P. Polo, http://dx.doi.org/10.4310/mrl.2018.v25.n1.a5 Dual BGG complexes for automorphic bundles , Math. Res. Lett. 25 (2018), no. 1, 85--141. 3818616
-
[25]
K.-W. Lan and B. Stroh, https://0-doi-org.pugwash.lib.warwick.ac.uk/10.1017/fms.2018.20 Compactifications of subschemes of integral models of S himura varieties , Forum Math. Sigma 6 (2018), e18, 105. 3859178
-
[26]
B. Le Stum, http://dx.doi.org/10.1017/CBO9780511543128 Rigid cohomology , Cambridge Tracts in Mathematics, vol. 172, Cambridge Univ. Press, 2007. 2358812
-
[27]
D. Loeffler, V. Pilloni, C. Skinner, and S. L. Zerbes, Higher H ida theory and p -adic L -functions for GSp _4 , preprint, 2019
work page 2019
-
[28]
D. Loeffler, C. Skinner, and S. L. Zerbes, http://arxiv.org/abs/1608.06112 Syntomic regulators of A sai-- F lach classes , preprint, 2016, arXiv:1608.06112
- [29]
-
[30]
B. Mazur and K. Rubin, Introduction to K olyvagin systems , Stark's conjectures: recent work and new directions, Contemp. Math., vol. 358, Amer. Math. Soc., Providence, RI, 2004, pp. 207--221. 2088718
work page 2004
-
[31]
Y. Mieda, Cycle classes, L efschetz trace formula and integrality for p -adic cohomology , Algebraic number theory and related topics 2007, RIMS K\^ o ky\^ u roku Bessatsu, B12, Res. Inst. Math. Sci. (RIMS), Kyoto, 2009, pp. 57--66. 2605773
work page 2007
-
[32]
J. Nekov \'a r and W. Nizio , http://dx.doi.org/10.2140/ant.2016.10.1695 Syntomic cohomology and p -adic regulators for varieties over p -adic fields , Algebra & Number Theory 10 (2016), no. 8, 1695--1790, with appendices by Laurent Berger and Fr\'ed\'eric D\'eglise. 3556797
-
[33]
Ohta, On the p -adic E ichler- S himura isomorphism for -adic cusp forms , J
M. Ohta, On the p -adic E ichler- S himura isomorphism for -adic cusp forms , J. Reine Angew. Math. 463 (1995), 49--98. 1332907
work page 1995
-
[34]
Local Whittaker-Newforms for GSp(4) matching to Langlands parameters
T. Okazaki, http://arxiv.org/abs/1902.07801 Local W hittaker-newforms for GSp (4) matching to L anglands parameters , preprint, 2019, arXiv:1902.07801
work page internal anchor Pith review Pith/arXiv arXiv 1902
-
[35]
I. I. Piatetski-Shapiro, http://dx.doi.org/10.2140/pjm.1997.181.259 L -functions for GSp _4 , Pacific J. Math. 181 (1997), no. 3, 259--275, Olga Taussky-Todd: in memoriam. 1610879
-
[36]
V. Pilloni, https://hal.archives-ouvertes.fr/hal-01393374/ Higher coherent cohomology and p -adic modular forms of singular weight , to appear in Duke Math. Jour., 2017
work page 2017
-
[37]
, Higher C oleman T heory , in preparation, 2020
work page 2020
-
[38]
B. Roberts and R. Schmidt, http://dx.doi.org/10.1007/978-3-540-73324-9 Local newforms for GSp (4) , Lecture Notes in Mathematics, vol. 1918, Springer, 2007. 2344630
-
[39]
M. R\"osner and R. Weissauer, http://arxiv.org/abs/1711.07409 Regular poles for spinor L -series attached to split B essel models of GSp (4) , preprint, 2017, arXiv:1711.07409
- [40]
-
[41]
Rubin, Euler systems, Annals of Mathematics Studies, vol
K. Rubin, Euler systems, Annals of Mathematics Studies, vol. 147, Princeton Univ. Press, 2000. 1749177
work page 2000
-
[42]
J. Tilouine, http://0-aif.cedram.org.pugwash.lib.warwick.ac.uk/item?id=AIF_2012__62_4_1383_0 Formes compagnons et complexe BGG dual pour GSp_4 , Ann. Inst. Fourier (Grenoble) 62 (2012), no. 4, 1383--1436. 3025747
work page 2012
-
[43]
Tilouine, Siegel varieties and p -adic S iegel modular forms , Doc
J. Tilouine, Siegel varieties and p -adic S iegel modular forms , Doc. Math. (2006), no. Extra Vol., 781--817. 2290605
work page 2006
-
[44]
E. Urban, Sur les repr\'esentations p -adiques associ\'ees aux repr\'esentations cuspidales de GSp _4 / , Ast \'e risque 302 (2005), 151--176, Formes automorphes. II. Le cas du groupe GSp (4) . 2234861
work page 2005
-
[45]
J.-L. Waldspurger, Une variante d'un r\'esultat de A izenbud, G ourevitch, R allis et S chiffmann , Ast \'e risque 346 (2012), 313--318, Sur les conjectures de Gross et Prasad. I. 3202559
work page 2012
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