In the EinsteinMaxwell theory the Weak Gravity Conjecture follows exactly from the positivity bounds on the scattering amplitudes imposed by locality, Lorentz invariance and unitarity of the Smatrix. However, this is in general not true anymore for theories beyond the pure EinsteinMaxwell. An interesting possibility to restore this equivalence is to require the theory to preserve electromagnetic duality. In this work we explore this idea in the context of the axiondilatonMaxwellEinstein theory. First, we study the duality group of this theory and we analytically derive its dualitypreserving, 4derivatives extension. Then, we determine the subset of values of the higherorder coefficients that realizes the Weak Gravity Conjecture by studying the corrections to the chargetomass ratio of a black hole solution of such extended theory. Finally, we compare such constraints with the positivity bounds on the scattering amplitudes in order to check the claimed equivalence between the two requirements.
Duality and the Weak Gravity Conjecture
Casagrande, Gabriele
2021/2022
Abstract
In the EinsteinMaxwell theory the Weak Gravity Conjecture follows exactly from the positivity bounds on the scattering amplitudes imposed by locality, Lorentz invariance and unitarity of the Smatrix. However, this is in general not true anymore for theories beyond the pure EinsteinMaxwell. An interesting possibility to restore this equivalence is to require the theory to preserve electromagnetic duality. In this work we explore this idea in the context of the axiondilatonMaxwellEinstein theory. First, we study the duality group of this theory and we analytically derive its dualitypreserving, 4derivatives extension. Then, we determine the subset of values of the higherorder coefficients that realizes the Weak Gravity Conjecture by studying the corrections to the chargetomass ratio of a black hole solution of such extended theory. Finally, we compare such constraints with the positivity bounds on the scattering amplitudes in order to check the claimed equivalence between the two requirements.File  Dimensione  Formato  

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https://hdl.handle.net/20.500.12608/21774