0023-6152

AA00697606

1526294

Unrefereed

0023-6152

AA00697606

This study was conducted to apply Bondi K–factor to the expansion analysis of the toy space model under the change in v (velocity) from –c to c (speed of light in vacuum). Mathematical hypotheses (A) ~ (E) were suggested. (A) Bondi K–factor and its reciprocal were regarded as the toy space model in relative size and the toy energy density model in relative size, respectively. (B) If v = –c, then the size of the toy space model was 0 and the density of the toy energy model was ∞, a singular point that was under the control of the invariant. (C) The tiny toy space model was born from 0 or from the wave phenomenon, under something like a renormalization of infinities resolving the problem of the singular point. (D) The newborn tiny toy space model showed an early rapid expansion under the decelerated expansion that continued until the inflection point [v = –c/2, redshift = 0.732, the time of the middle between the birth (v = –c) and the present (v = 0) under a hypothetical condition], and then turned into the accelerated expansion. (E) If v = c, then the size of the toy space model was ∞ and the density of the toy energy model was 0, a singular point under the control of the invariant. The fate of the toy space model, an explosion or an everlasting expansion, would depend on the rate at which v would change with time. This study suggested a mathematical hypothesis that Bondi K–factor and its reciprocal gave a toy space model showing a relativistic expansion under the change in v from –c to c.