Tag 0224

\(D_{17}^{*}\)

D17*

Invariants

Rank17
Signature \((n_+, n_-)\)(17, 0)
Determinant\(\tfrac{1}{4}\)

Gram tensor

The components \(b(e_i, e_j)\) of the Gram tensor \(b\) in the chosen basis \(e_{1}, \dots, e_{17}\).

\(e_{1}\)\(e_{2}\)\(e_{3}\)\(e_{4}\)\(e_{5}\)\(e_{6}\)\(e_{7}\)\(e_{8}\)\(e_{9}\)\(e_{10}\)\(e_{11}\)\(e_{12}\)\(e_{13}\)\(e_{14}\)\(e_{15}\)\(e_{16}\)\(e_{17}\)
\(e_{1}\)1111111111111111/21/2
\(e_{2}\)12222222222222211
\(e_{3}\)1233333333333333/23/2
\(e_{4}\)12344444444444422
\(e_{5}\)1234555555555555/25/2
\(e_{6}\)12345666666666633
\(e_{7}\)1234567777777777/27/2
\(e_{8}\)12345678888888844
\(e_{9}\)1234567899999999/29/2
\(e_{10}\)12345678910101010101055
\(e_{11}\)12345678910111111111111/211/2
\(e_{12}\)12345678910111212121266
\(e_{13}\)12345678910111213131313/213/2
\(e_{14}\)12345678910111213141477
\(e_{15}\)12345678910111213141515/215/2
\(e_{16}\)1/213/225/237/249/2511/2613/2715/217/415/4
\(e_{17}\)1/213/225/237/249/2511/2613/2715/215/417/4
[[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, 1, 1], [1, 2, 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, 2, 2], [1, 2, 3, 4, 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, 3, 3], [1, 2, 3, 4, 5, 6, 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, 4, 4], [1, 2, 3, 4, 5, 6, 7, 8, 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, 5, 5], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 11, 11, 11, 11/2, 11/2], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 12, 12, 12, 6, 6], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13, 13, 13/2, 13/2], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 14, 7, 7], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 15/2, 15/2], [1/2, 1, 3/2, 2, 5/2, 3, 7/2, 4, 9/2, 5, 11/2, 6, 13/2, 7, 15/2, 17/4, 15/4], [1/2, 1, 3/2, 2, 5/2, 3, 7/2, 4, 9/2, 5, 11/2, 6, 13/2, 7, 15/2, 15/4, 17/4]]

Definite lattice

Minimum of \(b(x, x)\), \(x \neq 0\)\(1\)
Kissing number34
Order of the isometry group\(46620662575398912000 = 2^{32} \cdot 3^{6} \cdot 5^{3} \cdot 7^{2} \cdot 11 \cdot 13 \cdot 17\)

Roots

Root lattice: \(L = \mathbb{Z}\Phi(L)\)no
Number of roots578
\(R(L) = \mathbb{Z}\Phi(L)\)\(\cong \mathrm{I}_{17,0}\)
Rank of \(R(L)\)17
\([L : R(L)]\)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\(\mathbb{Z}\Phi_c\)
\(\Phi_{1}\)\(B_{17}\)\(\{1, 2\}\)578\(\cong \mathrm{I}_{17,0}\)

Simple roots

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