The maximum value of a occurs when the integral diverges, which is when
26
Expression 27: left parenthesis, 1 plus varepsilon , right parenthesis "a" to the negative 1st power minus varepsilon equals 01+εa−1−ε=0
27
So
28
Expression 29: "a" Subscript, "m" "a" "x" , Baseline equals StartFraction, varepsilon plus 1 Over varepsilon , EndFractionamax=ε+1ε
equals=
2.2 6 5 8 2 2 7 8 4 8 12.26582278481
29
As the maximum occurs at exactly halfway through the lifetime of a close universe, it's total lifetime is
30
Expression 31: StartFraction, 2 Over "H" Subscript, 0 , Baseline , EndFraction Start integral from 0 to StartFraction, varepsilon plus 1 Over varepsilon , EndFraction , end integral, StartFraction, 1 Over StartRoot, left parenthesis, 1 plus varepsilon , right parenthesis "a" to the negative 1st power minus varepsilon , EndRoot , EndFraction "d" "a"2H0∫ε+1ε011+εa−1−εda
31
Now we need to find a value for H_0 that means its evolution matches with the matter-dominated era of the LCDM model.
32
As the scale factor goes to zero, the integrand goes to
33
Expression 34: StartFraction, 1 Superscript, , Baseline Over StartRoot, left parenthesis, 1 plus varepsilon , right parenthesis "a" to the negative 1st power , EndRoot , EndFraction11+εa−1
34
Similiarly for the LCDM model (ignoring the radiation-dominated era) the integrand goes to
35
Expression 36: StartFraction, 1 Superscript, , Baseline Over StartRoot, Omega Subscript, "m" 0 "L" "C" "D" "M" , Baseline "a" to the negative 1st power , EndRoot , EndFraction1Ωm0LCDMa−1
36
Using
37
Expression 38: StartFraction, StartRoot, StartNestedFraction, 1 plus varepsilon NestedOver Omega Subscript, "m" 0 "L" "C" "D" "M" , Baseline , EndNestedFraction , EndRoot Superscript, , Baseline Over StartRoot, left parenthesis, 1 plus varepsilon , right parenthesis "a" to the negative 1st power , EndRoot , EndFraction equals StartFraction, 1 Superscript, , Baseline Over StartRoot, Omega Subscript, "m" 0 "L" "C" "D" "M" , Baseline "a" to the negative 1st power , EndRoot , EndFraction1+εΩm0LCDM1+εa−1=1Ωm0LCDMa−1
38
the integral below converges to the early LCDM universe
39
Expression 40: StartFraction, 1 Superscript, , Baseline Over "H" Subscript, 0 "L" "C" "M" , Baseline , EndFraction Start integral from 0 to "a" , end integral, StartFraction, StartRoot, StartNestedFraction, 1 plus varepsilon NestedOver Omega Subscript, "m" 0 "L" "C" "D" "M" , Baseline , EndNestedFraction , EndRoot Superscript, , Baseline Over StartRoot, left parenthesis, 1 plus varepsilon , right parenthesis "a" prime to the negative 1st power minus varepsilon , EndRoot , EndFraction "d" "a" prime1H0LCM∫a01+εΩm0LCDM1+εa′−1−εda′
40
Moving the constant outside the integral we find that:
Expression 44: "t" Subscript, "t" "o" "t" "a" "l" , Baseline equals StartFraction, 2 StartRoot, StartNestedFraction, 1 plus varepsilon NestedOver Omega Subscript, "m" 0 "L" "C" "D" "M" , Baseline , EndNestedFraction , EndRoot Over "H" Subscript, 0 "L" "C" "D" "M" , Baseline , EndFraction Start integral from 0 to StartFraction, varepsilon plus 1 Over varepsilon , EndFraction , end integral, StartFraction, 1 Over StartRoot, left parenthesis, 1 plus varepsilon , right parenthesis "a" to the negative 1st power minus varepsilon , EndRoot , EndFraction "d" "a"ttotal=21+εΩm0LCDMH0LCDM∫ε+1ε011+εa−1−εda