Tag 0166

\(\Lambda_{13}\)

Lambda13·LAMBDA13

Invariants

Rank13
Signature \((n_+, n_-)\)(13, 0)
Determinant\(1024\)

Gram tensor

The components \(b(e_i, e_j)\) of the Gram tensor \(b\) in the chosen basis \(e_{1}, \dots, e_{13}\).

\(e_{1}\)\(e_{2}\)\(e_{3}\)\(e_{4}\)\(e_{5}\)\(e_{6}\)\(e_{7}\)\(e_{8}\)\(e_{9}\)\(e_{10}\)\(e_{11}\)\(e_{12}\)\(e_{13}\)
\(e_{1}\)4-200000000000
\(e_{2}\)-24-2200000000-1
\(e_{3}\)0-240020000002
\(e_{4}\)0204220000000
\(e_{5}\)0002420021000
\(e_{6}\)0022242212001
\(e_{7}\)0000024202000
\(e_{8}\)0000022402001
\(e_{9}\)0000210042000
\(e_{10}\)0000122224221
\(e_{11}\)0000000002422
\(e_{12}\)0000000002241
\(e_{13}\)0-120010101214
[[4, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [-2, 4, -2, 2, 0, 0, 0, 0, 0, 0, 0, 0, -1], [0, -2, 4, 0, 0, 2, 0, 0, 0, 0, 0, 0, 2], [0, 2, 0, 4, 2, 2, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 2, 4, 2, 0, 0, 2, 1, 0, 0, 0], [0, 0, 2, 2, 2, 4, 2, 2, 1, 2, 0, 0, 1], [0, 0, 0, 0, 0, 2, 4, 2, 0, 2, 0, 0, 0], [0, 0, 0, 0, 0, 2, 2, 4, 0, 2, 0, 0, 1], [0, 0, 0, 0, 2, 1, 0, 0, 4, 2, 0, 0, 0], [0, 0, 0, 0, 1, 2, 2, 2, 2, 4, 2, 2, 1], [0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 4, 2, 2], [0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 4, 1], [0, -1, 2, 0, 0, 1, 0, 1, 0, 1, 2, 1, 4]]

Integral lattice

Parityeven
Discriminant group\((\mathbb{Z}/2)^{4} \oplus (\mathbb{Z}/4)^{3}\)
Unimodularno
Integral overlattices \(L \subseteq M \subseteq L^*\)not decided
Primes of bad reduction \(\Sigma_L = \{p \mid 2 \det L\}\)\(\{2\}\)
Zeta function of the cone \(X_0 : Q(x) = 0\), \(\Sigma = \Sigma_L\)\(\zeta^\Sigma(X_0, s) = \zeta^\Sigma(s - 12)\)
Zeta function of \(X_n : Q(x) = n\), \(n \neq 0\), \(\Sigma = \Sigma_L \cup \{p \mid n\}\)\(\zeta^\Sigma(X_n, s) = \zeta^\Sigma(s - 12)\, L^\Sigma(s - 6, \chi_{1024n})\)
Genus symbol\(\mathrm{II}_{13,0}\ \bigl(2\colon 1^{6}:2^{4}\,[4^{3}]_{5}\bigr)\)

Definite lattice

Minimum of \(b(x, x)\), \(x \neq 0\)\(4\)
Kissing number906
Order of the isometry group\(4718592 = 2^{19} \cdot 3^{2}\)

Theta series

\[ \sum_{x \in L} q^{b(x, x)} = 1 + 906q^{4} + O(q^{5}) \]

Roots

Root lattice: \(L = \mathbb{Z}\Phi(L)\)no
Number of roots26
\(R(L) = \mathbb{Z}\Phi(L)\)\(\cong \langle 4 \rangle^{13}\)
Rank of \(R(L)\)13
\([L : R(L)]\)256
\(R(L)\) is primitive in \(L\)no: \(L / R(L) \cong (\mathbb{Z}/2)^{8}\)

Components of \(\Phi(L)\)

ComponentTypeValues of \(b(r, r)\)Number of roots\(\mathbb{Z}\Phi_c\)
\(\Phi_{1}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{2}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{3}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{4}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{5}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{6}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{7}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{8}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{9}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{10}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{11}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{12}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)
\(\Phi_{13}\)\(A_{1}\)\(\{4\}\)2\(\cong \langle 4 \rangle\)

Simple roots

\(\alpha^{(c)}_j\) is simple root \(j\) of the component \(\Phi_c\).

Simple rootCoordinates\(b(r, r)\)
\(\alpha^{(1)}_{1}\)\(e_{11}\)\(4\)
\(\alpha^{(2)}_{1}\)\(e_{7}\)\(4\)
\(\alpha^{(3)}_{1}\)\(e_{4}\)\(4\)
\(\alpha^{(4)}_{1}\)\(e_{3}\)\(4\)
\(\alpha^{(5)}_{1}\)\(e_{3} + e_{4} - 2e_{6} + 2e_{10} - e_{11}\)\(4\)
\(\alpha^{(6)}_{1}\)\(e_{3} + e_{4} - 2e_{6} + e_{7}\)\(4\)
\(\alpha^{(7)}_{1}\)\(e_{1}\)\(4\)
\(\alpha^{(8)}_{1}\)\(e_{1} + 2e_{2} + e_{3} - e_{4}\)\(4\)
\(\alpha^{(9)}_{1}\)\(e_{1} + 2e_{2} + 2e_{3} - e_{4} + 2e_{5} - 2e_{6} - 2e_{9} + 2e_{10} - e_{11}\)\(4\)
\(\alpha^{(10)}_{1}\)\(e_{1} + 2e_{2} + 2e_{3} - e_{4} + 2e_{5} - 2e_{6} + e_{7}\)\(4\)
\(\alpha^{(11)}_{1}\)\(e_{1} + 2e_{2} + 3e_{3} + 2e_{5} - 4e_{6} - 2e_{9} + 4e_{10} - e_{11} - 2e_{12}\)\(4\)
\(\alpha^{(12)}_{1}\)\(e_{1} + 2e_{2} + 3e_{3} + 2e_{5} - 4e_{6} + e_{7} + 2e_{8}\)\(4\)
\(\alpha^{(13)}_{1}\)\(e_{1} + 2e_{2} + 4e_{3} + 2e_{5} - 4e_{6} + e_{7} + 2e_{8} + e_{11} - 2e_{13}\)\(4\)

Notes

The Gram tensor is the section GRAM of the entry LAMBDA13 of the Catalogue of Lattices.

The catalogue entry gives this reference text: 1. SPLAG p. 157. 2. W.Plesken, M.Pohst, Constructing integral lattices with prescribed minimum II, Math. Comp. Vol 60, N. 202 (1993) 817-825

References

  1. G. Nebe and N. J. A. Sloane, Catalogue of Lattices, entry LAMBDA13. https://www.math.rwth-aachen.de/~Gabriele.Nebe/LATTICES/LAMBDA13.html