@article{31982,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>We show that for a generic conformal metric perturbation of a compact hyperbolic 3-manifold <jats:inline-formula><jats:alternatives><jats:tex-math>$$\Sigma $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
                  <mml:mi>Σ</mml:mi>
                </mml:math></jats:alternatives></jats:inline-formula> with Betti number <jats:inline-formula><jats:alternatives><jats:tex-math>$$b_1$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
                  <mml:msub>
                    <mml:mi>b</mml:mi>
                    <mml:mn>1</mml:mn>
                  </mml:msub>
                </mml:math></jats:alternatives></jats:inline-formula>, the order of vanishing of the Ruelle zeta function at zero equals <jats:inline-formula><jats:alternatives><jats:tex-math>$$4-b_1$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
                  <mml:mrow>
                    <mml:mn>4</mml:mn>
                    <mml:mo>-</mml:mo>
                    <mml:msub>
                      <mml:mi>b</mml:mi>
                      <mml:mn>1</mml:mn>
                    </mml:msub>
                  </mml:mrow>
                </mml:math></jats:alternatives></jats:inline-formula>, while in the hyperbolic case it is equal to <jats:inline-formula><jats:alternatives><jats:tex-math>$$4-2b_1$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
                  <mml:mrow>
                    <mml:mn>4</mml:mn>
                    <mml:mo>-</mml:mo>
                    <mml:mn>2</mml:mn>
                    <mml:msub>
                      <mml:mi>b</mml:mi>
                      <mml:mn>1</mml:mn>
                    </mml:msub>
                  </mml:mrow>
                </mml:math></jats:alternatives></jats:inline-formula>. This is in contrast to the 2-dimensional case where the order of vanishing is a topological invariant. The proof uses the microlocal approach to dynamical zeta functions, giving a geometric description of generalized Pollicott–Ruelle resonant differential forms at 0 in the hyperbolic case and using first variation for the perturbation. To show that the first variation is generically nonzero we introduce a new identity relating pushforwards of products of resonant and coresonant 2-forms on the sphere bundle <jats:inline-formula><jats:alternatives><jats:tex-math>$$S\Sigma $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
                  <mml:mrow>
                    <mml:mi>S</mml:mi>
                    <mml:mi>Σ</mml:mi>
                  </mml:mrow>
                </mml:math></jats:alternatives></jats:inline-formula> with harmonic 1-forms on <jats:inline-formula><jats:alternatives><jats:tex-math>$$\Sigma $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
                  <mml:mi>Σ</mml:mi>
                </mml:math></jats:alternatives></jats:inline-formula>.</jats:p>}},
  author       = {{Cekić, Mihajlo and Delarue, Benjamin and Dyatlov, Semyon and Paternain, Gabriel P.}},
  issn         = {{0020-9910}},
  journal      = {{Inventiones mathematicae}},
  keywords     = {{General Mathematics}},
  number       = {{1}},
  pages        = {{303--394}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{The Ruelle zeta function at zero for nearly hyperbolic 3-manifolds}}},
  doi          = {{10.1007/s00222-022-01108-x}},
  volume       = {{229}},
  year         = {{2022}},
}

@article{34890,
  abstract     = {{We prove that the 4-rank of class groups of quadratic number fields behaves as predicted in an extension due to Gerth of the Cohen–Lenstra heuristics. }},
  author       = {{Fouvry, Étienne and Klüners, Jürgen}},
  issn         = {{0020-9910}},
  journal      = {{Inventiones mathematicae}},
  keywords     = {{General Mathematics}},
  number       = {{3}},
  pages        = {{455--513}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{On the 4-rank of class groups of quadratic number fields}}},
  doi          = {{10.1007/s00222-006-0021-2}},
  volume       = {{167}},
  year         = {{2006}},
}

