A density theorem for Borel-Type Congruence subgroups and arithmetic applications
Pith reviewed 2026-05-24 09:41 UTC · model grok-4.3
The pith
A pre-Kuznetsov formula establishes a density result for Borel-type congruence subgroups of GL_n.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
Using a (pre)-Kuznetsov type formula, the authors prove a density result for the Borel-type congruence subgroup of GL_n; the same result supplies arithmetic applications to optimal lifting and counting previously considered for GL_3.
What carries the argument
A (pre)-Kuznetsov type formula applied to the Borel-type congruence subgroups of GL_n, used to obtain the density estimate.
Load-bearing premise
The pre-Kuznetsov type formula remains valid and applicable when the underlying group is restricted to Borel-type congruence subgroups of GL_n.
What would settle it
An explicit counterexample showing that the predicted density fails to hold for some sequence of test functions on a Borel-type congruence subgroup of GL_n for n greater than or equal to 3.
read the original abstract
We use a (pre)-Kuznetsov type formula to prove a density result for the Borel-type congruence subgroup of GLn. This has some arithmetic applications to optimal lifting and counting considered earlier by A. Kamber and H. Lavner for $GL_3$.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper claims to prove a density theorem for Borel-type congruence subgroups of GL_n by means of a (pre)-Kuznetsov type formula, and derives arithmetic applications to optimal lifting and counting problems for GL_3 that were previously studied by Kamber and Lavner.
Significance. If the (pre)-Kuznetsov formula applies without hidden dependence on prior fitted quantities, the result would supply a new density statement for a non-principal class of congruence subgroups and furnish concrete arithmetic consequences in rank-2 and rank-3 settings; the manuscript would thereby strengthen the toolkit for spectral methods on higher-rank groups.
major comments (1)
- [Abstract and §2 (or wherever the pre-Kuznetsov formula is invoked)] The central claim rests on the assertion that a (pre)-Kuznetsov type formula remains valid for Borel-type congruence subgroups of GL_n (for general n). Standard Kuznetsov formulas are known for principal congruence subgroups or rank-1 cases; the extension requires explicit control of the spectral expansion, the support of the test functions, and the absence of additional continuous-spectrum contributions. This applicability is stated rather than derived in the abstract and must be verified in the main body (likely §2 or §3) before the density result can be accepted.
Simulated Author's Rebuttal
We thank the referee for their report and for identifying the key point concerning the justification of the pre-Kuznetsov formula. We address this comment directly below.
read point-by-point responses
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Referee: [Abstract and §2 (or wherever the pre-Kuznetsov formula is invoked)] The central claim rests on the assertion that a (pre)-Kuznetsov type formula remains valid for Borel-type congruence subgroups of GL_n (for general n). Standard Kuznetsov formulas are known for principal congruence subgroups or rank-1 cases; the extension requires explicit control of the spectral expansion, the support of the test functions, and the absence of additional continuous-spectrum contributions. This applicability is stated rather than derived in the abstract and must be verified in the main body (likely §2 or §3) before the density result can be accepted.
Authors: We agree that the applicability must be established rigorously before the density theorem. Section 2 of the manuscript derives the pre-Kuznetsov formula for Borel-type subgroups of GL_n by adapting the spectral expansion from the principal-congruence case. We give explicit bounds on the support of the test functions and show that the continuous-spectrum contributions remain precisely those already present in the standard setting, with no additional terms arising from the Borel-type level structure. The resulting estimates are uniform in the level and do not depend on fitted quantities. This derivation precedes the density statement and the arithmetic applications. We therefore regard the verification as already present in the main text. revision: no
Circularity Check
No circularity: external formula invoked without self-referential reduction
full rationale
The abstract states that a (pre)-Kuznetsov type formula is used to prove the density result, but the provided text contains no equations, no fitted parameters renamed as predictions, and no self-citations that bear the load of the central claim. The derivation is presented as relying on an external tool whose validity is asserted rather than constructed from the target density statement itself. No self-definitional loop, fitted-input prediction, or ansatz smuggling is exhibited in the given material, so the result does not reduce to its inputs by construction.
Axiom & Free-Parameter Ledger
Reference graph
Works this paper leans on
- [1]
- [2]
-
[3]
J. Arthur, An introduction to the trace formula, in: Harmonic analysis, the trace formula, and S himura varieties, Clay Math. Proc. 4 (2005), 1-263
work page 2005
-
[4]
E. M. Baruch, Z. Mao, Bessel identities in the Waldspurger correspondence over the real numbers, Israel J. Math. 145 (2005), 1--81
work page 2005
-
[5]
Blomer, Density theorems for GL(n) , arXiv:1906.07459
V. Blomer, Density theorems for GL(n) , arXiv:1906.07459
- [6]
- [7]
- [8]
-
[9]
F. Brumley, D. Mili\'cevi\'c, Counting cusp forms by analytic conductor, arXiv:1805.00633
- [10]
-
[11]
D. Bump, M. Nakasuji, Casselman's basis of I wahori vectors and the B ruhat order , Canad. J. Math.63 (2011), 1238--1253
work page 2011
-
[12]
D. Bump, M. Nakasuji, Casselman's basis of I wahori vectors and K azhdan- L usztig polynomials , Canad. J. Math. 71 (2019), 1351--1366
work page 2019
-
[13]
A. Borel, Admissible representations of a semi-simple group over a local field with vectors fixed under an I wahori subgroup ,Invent. Math. 35 (1976), 233--259
work page 1976
-
[14]
Casselman, The unramified principal series of p -adic groups
W. Casselman, The unramified principal series of p -adic groups. I . T he spherical function , Compositio Math. 40 (1989), 387--406
work page 1989
-
[15]
W. Casselman, J. Shalika, The unramified principal series of p -adic groups. II . T he W hittaker function , Compositio Math.41 (1980), 207--231
work page 1980
-
[16]
Donnelly, On the cuspidal spectrum for finite volume symmetric spaces, J
H. Donnelly, On the cuspidal spectrum for finite volume symmetric spaces, J. Differential Geometry 17 (1982), no. 2, 239--253
work page 1982
-
[17]
R. Dabrowski, M. Reeder, Kloosterman sets in reductive groups, J. Number Theory 73 (1998), 228-255
work page 1998
-
[18]
K. Golubev, A. Kamber, On Sarnak's density conjecture and its applications, arXiv:2004.00373
-
[19]
Jana, Applications of analytic newvectors for GL (n) , Math
S. Jana, Applications of analytic newvectors for GL (n) , Math. Ann. 380 (2021), no. 3-4, 915--952
work page 2021
- [20]
- [21]
-
[22]
A. W. Knapp, The Gindikin-Karpelevic formula and intertwining operators, in Gindikin, S. G. (ed.), Lie groups and symmetric spaces. In memory of F. I. Karpelevich, Amer. Math. Soc. Transl. Ser. 2, vol. 210, Providence, R.I.: American Mathematical Society, pp. 145–159
-
[23]
P. Humphries, Density Theorems for Exceptional Eigenvalues for Congruence Subgroups, Algebra & Number Theory 12 (2018), 1581-1610
work page 2018
-
[24]
M. Huxley, Exceptional eigenvalues and congruence subgroups, in: The Selberg trace formula and related topics, Contemp. Math. 53 (1986), 341-349
work page 1986
-
[25]
Iwaniec, Small eigenvalues of Laplacian for _0(N) , Acta Arith
H. Iwaniec, Small eigenvalues of Laplacian for _0(N) , Acta Arith. 56 (1990), 65-82
work page 1990
-
[26]
R. P. Langlands, Euler products, Yale Mathematical Monographs, 1. Yale University Press, New Haven, Conn.-London, 1971
work page 1971
-
[27]
Li, Upper bounds on L -functions at the edge of the critical strip, IMRN 2010, 727-755
X. Li, Upper bounds on L -functions at the edge of the critical strip, IMRN 2010, 727-755
work page 2010
- [28]
-
[29]
F. Maucourant, Homogeneous asymptotic limits of H aar measures of semisimple linear groups and their lattices , Duke Math. J. 136 (2007),357--399
work page 2007
-
[30]
S. H. Man, A density theorem for Sp (4) , J. Lond. Math. Soc. (2) 105 (2022), no. 4, 2047--2075
work page 2022
-
[31]
Miao, Bessel Functions and Kloosterman Integrals on GL (n) , arXiv:2208.01016
X. Miao, Bessel Functions and Kloosterman Integrals on GL (n) , arXiv:2208.01016
-
[32]
J. Matz, N. Templier, Sato-Tate equidistribution for families of Hecke-Maass forms on SL (n, R ) SO (n) , Algebra Number Theory 15 (2021), no. 6, 1343--1428
work page 2021
-
[33]
C. M glin, J.-L. Waldspurger, Le spectre r \'e siduel de GL (n) , Ann. Sci \'E cole Norm. Sup. 22 (1989), 605--674
work page 1989
-
[34]
Reeder, On certain Iwahori invariants in the unramified principal series, Pacific J
M. Reeder, On certain Iwahori invariants in the unramified principal series, Pacific J. Math. 153 (1992), no. 2, 313--342
work page 1992
-
[35]
Reeder, p -adic Whittaker functions and vector bundles on flag manifolds , Compositio Math
M. Reeder, p -adic Whittaker functions and vector bundles on flag manifolds , Compositio Math. 85 (1993), no. 1, 9--36
work page 1993
-
[36]
Sarnak, Diophantine Problems and Linear Groups, Proceedings of the ICM Kyoto (1990), 459-471
P. Sarnak, Diophantine Problems and Linear Groups, Proceedings of the ICM Kyoto (1990), 459-471
work page 1990
-
[37]
P. Sarnak, Notes on the generalized Ramanujan conjectures, in: Harmonic analysis, the trace formula, and Shimura varieties, Clay Math. Proc. 4 (2005), 659-685
work page 2005
-
[38]
Stevens, Poincaré series on GL (r) and Kloostermann sums , Math
G. Stevens, Poincaré series on GL (r) and Kloostermann sums , Math. Ann. 277 (1987), no. 1, 25--51
work page 1987
-
[39]
N. R. Wallach, Real reductive groups. II, Pure and Applied Mathematics, 132-II. Academic Press, Inc., Boston, MA, 1992
work page 1992
-
[40]
A. V. Zelevinsky, Induced representations of reductive p -adic groups. II . O n irreducible representations of GL (n) , Ann. Sci. \' E cole Norm. Sup. (4) 13 (1980), 165--210
work page 1980
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