# even lattice

A lattice $L$ in $\mathbb{R}^{n}$ is if the norm of every vector in $L$ is an even integer. Note that because of the polarization identity

 $(x,y)=\frac{(x+y,x+y)-(x,x)-(y,y)}{2}$

it follows that all scalar products in an even lattice are .

Title even lattice EvenLattice 2013-03-22 18:43:29 2013-03-22 18:43:29 monster (22721) monster (22721) 4 monster (22721) Definition msc 11H06