An Ignored Assumption of $\mathrm{\Lambda }$CDM Cosmology and An Old Question: Do We Live On The "Center" of The Universe?

We point out that $\mathrm{\Lambda }$CDM cosmology has an ignored assumption. That is, the $\mathrm{\Lambda }$ component of the universe moves synchronously with ordinary matters on Hubble scales. If cosmological constant is vacuum energy, this assumption may be very difficult to be understood. We then propose a new mechanism which can explain the accelerating recession of super-novaes. That is, considering the pressures originating from the random moving (including Hubble recession) of galaxy clusters and galaxies. We provide an new analytical solution of Einstein equation which may describe a universe whose pressures originating from the random moving of galaxy clusters and galaxies are considered.