56 The Quantum Structure of Space and Time
3.1.5.2
The equations of motion for the metric and 4 may be consistently obtained from
the Lagrangian
Hofava- Witten solution from Heterotic M-TheoryThe scalar field 4 characterises the size of the internal Calabi-Yau space.
3.1.5.3 Exact static supersymmetric solution
dsg = i? (-dt2 + dx2) + fi4 dG2 ,
ii = 1 + I;: 151,
- 4 = -3logH,
is a constant In the Hofava-Witten picture a second domain wall is introduce, at
y = L, by taking y to be periodic with period 2L, such that y = L is identified with
y = -L. Furthermore, one makes the 22 identification y t) -y.
Negative-tension Po sitiv *tension
Brane Eranet