Quantum mechanics does not imply that the world outside our past light cone is non-existent. The concept of the past light cone refers to the region of spacetime that can influence a given event based on the speed of light. It represents the limit of causally connected events to a particular point in spacetime.
The quantum eraser experiment is a thought experiment that explores the phenomenon of quantum entanglement and the wave-particle duality of light. In this experiment, the behavior of a particle's wave-like or particle-like properties can be influenced by measurements performed on its entangled partner, even if those measurements are outside the particle's past light cone.
However, it is important to note that the results of the quantum eraser experiment do not imply that the world outside our past light cone is non-existent. Quantum mechanics describes the behavior of particles and their interactions, including the phenomena of entanglement and wave-particle duality. These phenomena have been experimentally observed and verified within the framework of quantum mechanics.
While the quantum eraser experiment demonstrates the influence of measurements on entangled particles, it does not provide direct evidence or implications about the existence or non-existence of events or information outside our past light cone. The concept of events beyond the past light cone falls within the realm of speculative physics and is still an active area of research and theoretical exploration.