Resolving Lifshitz Horizons

Higher derivative corrections to Lifshitz backgrounds

“…However, one might argue that this kind of pathological behavior is simply a signal that our solutions should not be trusted in this particular regime and the singularity would presumably be resolved in a more complete string theory picture. Some compelling evidence supporting this point of view has been presented in [9,23,24]. The analysis of the previous section suggests a straightforward way of resolving the Lifshitz singularity: In general, a nonzero coupling of the dilaton to higher derivative terms will generate corrections to its effective potential.…”

“…Whether or not the solutions (3.29) are irrelevant depends on the choice of parameters. Although in general there is a mixing of φ with a and b due to the dilaton coupling to C 2 µνρσ , one can check that for g (φ) ≡ 0 the ansatz (3.29) reproduces the purely dilatonic perturbations of the two-derivative theory [9]. Although not technically correct, we will therefore still refer to those perturbations as "dilaton perturbations" in what follows.…”

“…As a consequence of the running dilaton, the Lifshitz solution runs into strong coupling either in the UV for the electrically charged solution or the IR for the magnetic solution (in the case d = 3). For the magnetic case, the possibility of quantum corrections was investigated in [9] by constructing a toy model where the gauge kinetic function picks up an expansion in the effective coupling g ≡ e − 1 2 λ 1 φ…”

Stability of Bianchi attractors in gauged supergravity

“…One of the important issues being investigated currently is the stability of such Lorentz violating geometries [18][19][20][21][22][23]. Instabilities due to scalar field fluctuations were found to exist in a class of charged black brane geometries [24,25].…”

“…Instabilities due to scalar field fluctuations were found to exist in a class of charged black brane geometries [24,25]. Presence of such instabilities in these solutions plays a crucial role because they indicate that the geometry might get corrected in the deep infrared [20]. Though the stability analysis has been carried out in a number of examples, a common recipe (to figure out whether certain geometry has any instability) is still lacking.…”