Heterotic M-theory in five dimensions

Abstract

We derive the five-dimensional effective action of strongly coupled heterotic string theory for the complete (1, 1) sector of the theory by performing a reduction, on a Calabi-Yau three-fold, of M-theory on S 1 /Z 2 . A crucial ingredient for a consistent truncation is a non-zero mode of the antisymmetric tensor field strength which arises due to magnetic sources on the orbifold planes.The correct effective theory is a gauged version of five-dimensional N = 1 supergravity coupled to Abelian vector multiplets, the universal hypermultiplet and four-dimensional boundary theories with gauge and gauge matter fields. The gauging is such that the dual of the four-form field strength in the universal multiplet is charged under a particular linear combination of the Abelian vector fields. In addition, the theory has potential terms for the moduli in the bulk as well as on the boundary. Because of these potential terms, the supersymmetric ground state of the theory is a multi-charged BPS three-brane domain wall, which we construct in general. We show that the five-dimensional theory together with this solution provides the correct starting point for particle phenomenology as well as early universe cosmology. As an application, we compute the four-dimensional N = 1 supergravity theory for the complete (1, 1) sector to leading nontrivial order by a reduction on the domain wall background. We find a correction to the matter field Kähler potential and threshold corrections to the gauge kinetic functions.

Hubble law and brane matter after ekpyrosis

“…Of course, we have studied only the simplified action used in [1]. The five-dimensional action of heterotic M-theory is much more complicated and can include a plethora of other moduli [8,9]. It remains to be seen whether this effect is a general feature of the ekpyrotic scenario, present in more complicated settings as well.…”

A critical review of classical bouncing cosmologies

“…These points were addressed in [121,122]. In [124], following earlier work in [125] and follow-up papers, it is argued that the predicted big bang is instead a big crunch and that computations in the ekpyrotic scenario need to be performed in the full 5d setup; more importantly, setting aside such potential theoretical concerns, the scenario was shown to be observationally problematic [126,127], since density fluctuations do not inherit a scale invariant spectrum, see below.…”

Towards supersymmetric cosmology in M-theory

“…The domain wall solutions [6] are generalized by introducing time dependence of their parametrs. This aproach can be justified [7] because the scale of the x 11 interval is lower than the Calabi-Yau scale. But one should check a posteriori whether the 11-dimensional equations of motion are satisfied and it is a very stringent requirement.…”

“…of the above equation may be nonzero for general vacuum expectation values of G given by eqs. (7)(8)(9)(10). However, as shown in ref.…”