phone: +46(0)18 471 3243
My research interests are in quantum field theory and supergravity, with a focus on formal aspects of scattering amplitudes in these theories. Scattering amplitudes can be used as a powerful tool to understand hidden symmetries and remarkable relations between different classes of theories. My work has led to the realization that a generic gravity theory can be formally understood as a product of two gauge theories.
Ultraviolet Properties of $\mathcal N = 8$ Supergravity at Five Loops2018-04-26
by: Bern, Zvi (UCLA) et al.
We use the recently developed generalized double-copy construction to obtain an improved representation of the five-loop four-point integrand of $N = 8$ supergravity whose leading ultraviolet behavior we analyze using state of the art loop-integral expansion and reduction methods. We find that the five-loop critical dimension where ultraviolet divergences first occur is $D_c=24/5$, corresponding to a $D^8 R^4$ counterterm. This ultraviolet behavior stands in contrast to the cases of four-dimensi...
Heterotic and bosonic string amplitudes via field theory2018-03-16
by: Azevedo, Thales (Uppsala U.) et al.
Previous work has shown that massless tree amplitudes of the type I and IIA/B superstrings can be dramatically simplified by expressing them as double copies between field-theory amplitudes and scalar disk/sphere integrals, the latter containing all the $\alpha'$-corrections. In this work, we pinpoint similar double-copy constructions for the heterotic and bosonic string theories using an $\alpha'$-dependen...
Gauged supergravities and spontaneous SUSY breaking from the double copy2017-10-25
Phys.Rev.Lett. 120 (2018) 171601
by: Chiodaroli, Marco (Santa Barbara, KITP) et al.
Supergravities with gauged R symmetry and Minkowski vacua allow for spontaneous supersymmetry breaking and, as such, provide a framework for building supergravity models of phenomenological relevance. In this Letter, we initiate the study of double copy constructions for these supergravities. We argue that, on general grounds, we expect their scattering amplitu...
Five-loop four-point integrand of $N=8$ supergravity as a generalized double copy2017-08-25
Phys.Rev. D96 (2017) 126012
by: Bern, Zvi (UCLA) et al.
We use the recently developed generalized double-copy procedure to construct an integrand for the five-loop four-point amplitude of N=8 supergravity. This construction starts from a naive double copy of the previously computed corresponding amplitude of N=4 super-Yang-Mills theory. This is then systematically modified by adding contact terms generated in the context of the method of maximal unitarity cut...
Conformal Gravity from Gauge Theory2017-07-11
by: Johansson, Henrik (Santa Barbara, KITP) et al.
We use the duality between color and kinematics to obtain scattering amplitudes in non-minimal conformal N=0,1,2,4 (super)gravity theories. Generic tree amplitudes can be constructed from a double copy between (super-)Yang-Mills theory and a new gauge theory built entirely out of dimension-six operators. The latter theory is marginal in six dimensions and contains modes with a wrong-sign propagator, echoing the behavior of conformal g...