Psi Energy Pulse (also known as Quantum Temporal Rift Event,  Arcing,  and Crossdimensional Shockwave ) is a Collected and Centralized Necromantic Convulsion or a large pulse of psychic energy capable of awakening sleeping spirits.
On the Thanksgiving 1991 holiday, Dr. Ilyssa Selwyn was going over the Gozer exhibit at the Natural History Museum when a pulse of blue light surged through the building. The pulse encompassed New York and began Ivo Shandor's plans. In addition to creating a high level of spiritual turbulence and paranormal activity, the pulse also placed Dr. Selwyn in a deep dream-like trance,  returned Gozer in its Destructor form back to the physical plane, and created a crack in the Paranormal Containment Research Tank holding Slimer. Slimer took advantage of the situation and escaped from the Tank.
After defeating Gozer, Egon refers to the pulse as a Quantum Temporal Rift Event. Dr. Selwyn doesn't understand and Ray translates the term as arcing or a large pulse of psychic energy.
- In the third draft of the script, Ray calls it a Non-Centralized Necromantic Radiation.