Mathematical model describes and analyzes the state of entity σ when entering the time domain P

The time we perceive in everyday life is a normal concept but there is still no real answer to what is time? It is difficult for us to imagine that our minds and perceptions are placed in a universe with a huge amount of matter and extremely bustling events. This research designs a fictitious but feasible λ closed universe model. In this universe everything seems very simple, there exists only one mathematical entity called the entity σ and there is absolutely nothing else besides this entity. All events occurring in the universe λ are caused by the behavior of entity σ. The signal diagram is a time axis to measure time in λ. When the entity σ exists at a time on the time axis, it is clear that the previous times are all past times of σ in λ and the time domain. So let's assume entity σ can enter the time domain P on the signal diagram and then analyze how the state of λ will change. According to the butterfly effect, every small impact also creates big changes. The impacts of the entity σ in the time domain P, whether large or small, also create events that are different from the events that happened in λ, even the fact that σ exists in the time domain P is an impact. Because those event changes have created a different universe than the original universe, applying the multiverse theory, it can be said that σ entering the time domain P means σ entering a parallel universe. But it is still not possible for σ to enter a parallel universe, but research has come up with a method called the λ synchronous method. Because of the special properties of the closed universe system λ and the entity σ, it is entirely possible to create another closed universe system exactly like the original system, then all the events in the original system λ are recreated in the new system λ and adjusted so that events in the new λ begin to occur a period of time later. At this time, let the entity σ jump to the new λ system and one thing has completely happened: the entity σ has entered its own past. When using this method to let σ enter the time domain P, we can see that the time in the original λ system and the new λ system are events that occur in λ itself, when no events occur, or we can say when the entity σ is at rest, time is also considered to be standing still.