Here are a few classes of weapons for a post-singularity society.
1 FTL antimatter torpedoes: a faster than light torpedo carries an antimatter warhead. They never said what a "photon torpedo" was on Star Trek, but this would be a good description.
2 Exa-Watt laser cannons: matter anti-matter annihilation is the energy source for an XRay laser. The cannons are placed on FTL torpedoes so the XRay pulses arrive at the target faster than light.
3 Stellar core bombs: open a wormhole at the target and simultaneously open a wormhole at the core of a star. The stellar core material will shoot out at relativistic speeds.
4 Quantum vacuum disruptor: induces a collapse of the quantum vacuum state to a new low energy configuration. In the safe mode the disruption decays as it radiates from the target. In the Doomsday mode the disruption grows exponentially and engulfs the entire universe.