Abstract
Since the special relativity can be viewed as the physics in an inverse Wick rotation of four-dimensional (4D) Euclid space, which is at almost equal footing with the 4D Riemann/Lobachevski space, there should be important physics in the inverse Wick rotation of 4D Riemann/Lobachevski space. Thus, there are three kinds of special relativity in de Sitter(dS)/Minkowski/anti-de Sitter(AdS) space at almost equal footing, respectively. There is an instanton tunnelling scenario in the Riemann–de Sitter case that may explain why Λ be positive and link with the multiverse.