Rational homology
= Rational homology
{wiki}
Rational homology satisfies
$$
H_i(X;\mathbb Q)\cong H_i(X;\mathbb Z)\otimes_\mathbb Z\mathbb Q.
$$
It records the free rank of integral homology and discards torsion.
= Rational homology
{wiki}
Rational homology satisfies
$$
H_i(X;\mathbb Q)\cong H_i(X;\mathbb Z)\otimes_\mathbb Z\mathbb Q.
$$
It records the free rank of integral homology and discards torsion.