Universe includes visible universe and hidden universe, and visible universe includes positive universe and negative universe. Visible universe consists of three dimensions: real space and virtual time, while hidden universe consists of three dimensions: virtual space and real time. It can be seen that the universe and the hidden universe overlap and are mutually causal. Therefore, the imaginary number can be introduced into the Taiji universe model and the mathematical model of the Taiji universe model can be established. XYZ(X'y'z') and t represent real space three-dimensional and real time dimension respectively, and sub and ti represent virtual space three-dimensional and virtual time dimension respectively; XYZti Z'Y'X' stands for the visible universe, and Yi Xi ziT stands for the hidden universe; XYZti stands for positive matter universe (positive universe), and X'Y'Z'ti stands for antimatter universe (negative universe). From this, the universe and its branches can be represented by eleven dimensions, and the Taiji universe model (as shown in the figure) can be represented by XYZti Z'Y'X'xi yi ziT.

1 positive universe: XYZti (positive matter universe)

The positive universe is characterized by the tornado expansion of the positive matter universe, and the visible universe in which human beings live belongs to the positive universe. Observing the positive universe from the perspective of human beings, the positive universe presents a three-dimensional (XYZ) image with a virtual time dimension (ti, represented by an imaginary number), indicating that the universe presents positive material properties, while other dimensions of the universe present dark matter and dark energy properties.

2 negative universe: X'Y'Z'ti (antimatter universe)

There are two types of negative universe. One is the negative universe associated with the positive universe, which shows the supersymmetry of the positive universe and the negative universe. The negative universe displays a three-dimensional (X'Y'Z') image, and forms a parallel universe associated with the positive and antimatter universes with the virtual time dimension ti of the positive universe. One is the negative universe formed by the evolution of the positive universe, which shows the reverse regression of the universe; From the visible universe of human existence, this negative universe is characterized by an antimatter universe with internal rotation and water vortex, and its essence is the fracture, division and formation of the ultra-micro closed string of the universe.

3 tangible universe: XYZti Z'Y'X'

It can be seen that the universe is a collection of positive and negative universes, and the positive and negative universes are connected through the virtual time dimension ti. It can be seen that the universe is constantly created through the cosmic black hole (hidden universe), forming the endless characteristics of the big universe.

4 The Hidden Universe: Yi Xi Acne

The hidden universe is a four-dimensional space-time consisting of virtual space dimension (Yi Xi son, represented by imaginary number) and real time dimension T. Seen from the visible universe where human beings live, the hidden universe is in a one-dimensional linear string shape. From the infinite creation of the visible universe, the hidden universe shows the characteristics of cosmic strings and the topological defects of the universe, so the hidden universe and the visible universe show the mother-child relationship, the visible universe is constantly created from the hidden universe, and the visible universe is constantly annihilated into the hidden universe with evolution, thus forming the periodic characteristics of the big universe.

Five universes: XYZti Z'Y'X'xi yi ziT

The big universe is the unity of the visible universe and the hidden universe, which consists of eleven dimensions and has the characteristics of endless circulation.