Marco Baldi
Marco Baldi
Marco Baldi
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Time dependent couplings [MB 1005.2188]<br />
Why consider time variations of the coupling?<br />
1) There is no reason why β should be a constant. β(ϕ) is a more natural assumption<br />
2) A varying (growing) β could have larger effects on astrophysical observables at late<br />
times with a weaker impact on CMB and background expansion: INTERESTING.<br />
What changes with a time dependent coupling?<br />
There is no general analytic solution.<br />
Assume some generic forms of coupling evolution and find numerical solutions:<br />
<br />
1.000<br />
0.100<br />
0.010<br />
Background evolution<br />
MDE<br />
Growing MDE<br />
0.001<br />
-10 -8 -6 -4 -2 0<br />
N ln a<br />
Tuesday, July 6, 2010<br />
RP5 in <strong>Baldi</strong> et al. (2010)<br />
EXP010a2<br />
EXP015a3<br />
EXP010e2<br />
EXP010e3<br />
EXP015e3<br />
w <br />
1.0<br />
0.5<br />
0.0<br />
-0.5<br />
-1.0<br />
Equation of state<br />
RP5 in <strong>Baldi</strong> et al. (2010)<br />
EXP010a2<br />
EXP015a3<br />
EXP010e2<br />
EXP010e3<br />
EXP015e3<br />
1 10<br />
z + 1<br />
<strong>Marco</strong> <strong>Baldi</strong> - MGADS, Strasbourg 16 VI 2010<br />
β = β0a β1<br />
β = β0e β1φ/M
Change language