The body was stolen by the disciples to make it look as if Jesus had been resurrected.
The body was buried in one tomb temporarily and then put in the graveyard for criminals. The women found the tomb empty and thought he had been resurrected.
The disciples had experiences of Jesus that were hallucinatory.
Jesus wasn’t quite dead on the cross, and got out of his tomb claiming to be resurrected.
The women went to the wrong tomb.
Jesus had an unknown identical twin brother who began a hoax about the resurrection.
Anybody got a better theory?