Tag 0250

\(D_{19}^{*}\)

D19*

Invariants

Rank19
Signature \((n_+, n_-)\)(19, 0)
Determinant\(\tfrac{1}{4}\)

Gram tensor

The components \(b(e_i, e_j)\) of the Gram tensor \(b\) in the chosen basis \(e_{1}, \dots, e_{19}\).

\(e_{1}\)\(e_{2}\)\(e_{3}\)\(e_{4}\)\(e_{5}\)\(e_{6}\)\(e_{7}\)\(e_{8}\)\(e_{9}\)\(e_{10}\)\(e_{11}\)\(e_{12}\)\(e_{13}\)\(e_{14}\)\(e_{15}\)\(e_{16}\)\(e_{17}\)\(e_{18}\)\(e_{19}\)
\(e_{1}\)111111111111111111/21/2
\(e_{2}\)1222222222222222211
\(e_{3}\)123333333333333333/23/2
\(e_{4}\)1234444444444444422
\(e_{5}\)123455555555555555/25/2
\(e_{6}\)1234566666666666633
\(e_{7}\)123456777777777777/27/2
\(e_{8}\)1234567888888888844
\(e_{9}\)123456789999999999/29/2
\(e_{10}\)123456789101010101010101055
\(e_{11}\)123456789101111111111111111/211/2
\(e_{12}\)123456789101112121212121266
\(e_{13}\)123456789101112131313131313/213/2
\(e_{14}\)123456789101112131414141477
\(e_{15}\)123456789101112131415151515/215/2
\(e_{16}\)123456789101112131415161688
\(e_{17}\)123456789101112131415161717/217/2
\(e_{18}\)1/213/225/237/249/2511/2613/2715/2817/219/417/4
\(e_{19}\)1/213/225/237/249/2511/2613/2715/2817/217/419/4
[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1/2, 1/2], [1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1], [1, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3/2, 3/2], [1, 2, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 2, 2], [1, 2, 3, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5/2, 5/2], [1, 2, 3, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 3, 3], [1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7/2, 7/2], [1, 2, 3, 4, 5, 6, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 4, 4], [1, 2, 3, 4, 5, 6, 7, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9/2, 9/2], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 10, 10, 10, 10, 10, 10, 5, 5], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 11, 11, 11, 11, 11, 11/2, 11/2], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 12, 12, 12, 12, 12, 6, 6], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13, 13, 13, 13, 13/2, 13/2], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 14, 14, 14, 7, 7], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 15, 15, 15/2, 15/2], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 16, 8, 8], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 17/2, 17/2], [1/2, 1, 3/2, 2, 5/2, 3, 7/2, 4, 9/2, 5, 11/2, 6, 13/2, 7, 15/2, 8, 17/2, 19/4, 17/4], [1/2, 1, 3/2, 2, 5/2, 3, 7/2, 4, 9/2, 5, 11/2, 6, 13/2, 7, 15/2, 8, 17/2, 17/4, 19/4]]

Definite lattice

Minimum of \(b(x, x)\), \(x \neq 0\)\(1\)
Kissing number38
Order of the isometry group\(63777066403145711616000 = 2^{35} \cdot 3^{8} \cdot 5^{3} \cdot 7^{2} \cdot 11 \cdot 13 \cdot 17 \cdot 19\)

Roots

Root lattice: \(L = \mathbb{Z}\Phi(L)\)no
Number of roots722
\(R(L) = \mathbb{Z}\Phi(L)\)\(\cong \mathrm{I}_{19,0}\)
Rank of \(R(L)\)19
\([L : R(L)]\)2
\(R(L)\) is primitive in \(L\)no: \(L / R(L) \cong \mathbb{Z}/2\)

Components of \(\Phi(L)\)

ComponentTypeValues of \(b(r, r)\)Number of roots\(\mathbb{Z}\Phi_c\)
\(\Phi_{1}\)\(B_{19}\)\(\{1, 2\}\)722\(\cong \mathrm{I}_{19,0}\)

Simple roots

Simple rootCoordinates\(b(r, r)\)
\(\alpha_{1}\)\(e_{2}\)\(2\)
\(\alpha_{2}\)\(e_{1} - 2e_{2} + e_{3}\)\(2\)
\(\alpha_{3}\)\(e_{2} - 2e_{3} + e_{4}\)\(2\)
\(\alpha_{4}\)\(e_{3} - 2e_{4} + e_{5}\)\(2\)
\(\alpha_{5}\)\(e_{4} - 2e_{5} + e_{6}\)\(2\)
\(\alpha_{6}\)\(e_{5} - 2e_{6} + e_{7}\)\(2\)
\(\alpha_{7}\)\(e_{6} - 2e_{7} + e_{8}\)\(2\)
\(\alpha_{8}\)\(e_{7} - 2e_{8} + e_{9}\)\(2\)
\(\alpha_{9}\)\(e_{8} - 2e_{9} + e_{10}\)\(2\)
\(\alpha_{10}\)\(e_{9} - 2e_{10} + e_{11}\)\(2\)
\(\alpha_{11}\)\(e_{10} - 2e_{11} + e_{12}\)\(2\)
\(\alpha_{12}\)\(e_{11} - 2e_{12} + e_{13}\)\(2\)
\(\alpha_{13}\)\(e_{12} - 2e_{13} + e_{14}\)\(2\)
\(\alpha_{14}\)\(e_{13} - 2e_{14} + e_{15}\)\(2\)
\(\alpha_{15}\)\(e_{14} - 2e_{15} + e_{16}\)\(2\)
\(\alpha_{16}\)\(e_{15} - 2e_{16} + e_{17}\)\(2\)
\(\alpha_{17}\)\(e_{16} - 2e_{17} + e_{18} + e_{19}\)\(2\)
\(\alpha_{18}\)\(e_{17} - 2e_{18}\)\(2\)
\(\alpha_{19}\)\(e_{18} - e_{19}\)\(1\)