Could vacuum energy dim standard candles? It is assumed that particles and anti-particles pop out in vacuum (vacuum energy). Could this have an effect on the paths of photons when they interact with these particles? The amount of photons going straight from the source would then gradually diminish. The supernovae would then appear dimmer than without this effect.
Locally, energy and momentum must be conserved. So no, a photon cannot lose energy or change momentum by interacting with virtual particle pairs that have a net energy and momentum of zero.