Winding out of the Swamp: Evading the weak gravity conjecture with F -term winding inflation?

Abstract

We present a new model of large field inflation along a winding trajectory in the field space of two axionic fields, where the "axions" originate from the complex structure moduli sector of a Calabi-Yau 3-fold at large complex structure. The winding trajectory arises from fixing one combination of axions by bulk fluxes and allows for a transplanckian effective field range. The inflaton potential arises from small "instantonic" corrections to the geometry and realises natural inflation. By working in a regime of large complex structure for two complex structure moduli the inflaton potential can be made subdominant without severe tuning. We also discuss the impact of the recent 'no-go theorems' for transplanckian axion periodicities on our work. Interestingly, our setup seems to realise a loophole pointed out in arXiv:1503.00795 and arXiv:1503.04783: our construction is a candidate for a string theory model of large field inflation which is consistent with the mild form of the weak gravity conjecture for axions. arXiv:1503.07912v4 [hep-th]

On axionic field ranges, loopholes and the weak gravity conjecture

“…Indeed, an idea to evade the stringent bound on the axion field range has been suggested in [5] and [1]. This suggestion has recently been taken up by [21,22]. We will elaborate further on this idea and point out a number of hurdles that putative large field inflation models would need to overcome.…”

Can gravitational instantons really constrain axion inflation?

“…12 Then |θ is an eigenbasis of the Hamiltonian with eigenvalues V (θ). We see by comparison with (3.26) that V (θ) = 2 cos θKe −S 0 .…”

Complexity is simple!

“…10 Thus, we are fixing one overall constant, but the bound is non-trivially satisfied as other parameters are varied, e.g., mass, rotation, and dimension. 11 The violation for small black holes seems to have been neglected in [1] and pointed out subsequently in [48].…”