On scalar radiation

We discuss radiation in theories with scalar fields. Our key observation is that even in flat spacetime, the radiative fields depend qualitatively on the coupling of the scalar field to the Ricci scalar: for non-minimally coupled scalars, the radiative energy density is not positive definite, the radiated power is not Lorentz invariant and it depends on the derivative of the acceleration. We explore implications of this observation for radiation in conformal field theories. First, we find a relation between two coefficients that characterize radiation, that holds in all the conformal field theories we consider. Furthermore, we find evidence that for a 1/2-BPS probe coupled to N = 4 super Yang-Mills, and following an arbitrary trajectory, the spacetime dependence of the one-point function of the energy momentum tensor is independent of the Yang-Mills coupling

Energy Loss of an Infinitely Massive Half-Bogomol'nyi-Prasad-Sommerfeld Particle by Radiation to All Orders in 1/N

We use the AdS/CFT correspondence to compute the energy radiated by an infinitely massive half-Bogomol'nyi-Prasad-Sommerfeld particle charged under N = 4 super Yang-Mills theory, transforming in the symmetric or antisymmetric representation of the gauge group, and moving in the vacuum, to all orders in 1 / N and for large 't Hooft coupling. For the antisymmetric case we consider D 5 -branes reaching the boundary of five-dimensional anti-de Sitter space ( AdS 5 ) at arbitrary timelike trajectories, while for the symmetric case, we consider a D 3 -brane in AdS 5 that reaches the boundary at a hyperbola. We compare our results to the one obtained for the fundamental representation, deduced by considering a string in AdS 5

Exact bremsstrahlung function in N=2 superconformal field theories

We propose an exact formula for the energy radiated by an accelerating quark in N = 2 superconformal theories in four dimensions. This formula reproduces the known bremsstrahlung function for N = 4 theories and provides a prediction for all the perturbative and instanton corrections in N = 2 theories. We perform a perturbative check of our proposal up to three loops

Probing N=2 superconformal field theories with localization

We use supersymmetric localization to study probes of four dimensional Lagrangian N=2 superconformal field theories. We first derive a unique equation for the eigenvalue density of these theories. We observe that these theories have a Wigner eigenvalue density precisely when they satisfy a necessary condition for having a holographic dual with a sensible higher-derivative expansion. We then compute in the saddle-point approximation the vacuum expectation value of 1/2-BPS circular Wilson loops, and the two-point functions of these Wilson loops with the Lagrangian density and with the stress-energy tensor. This last computation also provides the corresponding Bremsstrahlung functions and entanglement entropies. As expected, whenever a finite fraction of the matter is in the fundamental representation, the results are drastically different from those of N=4 supersymmetric Yang-Mills theory

The planar limit of N=2 superconformal field theories

We obtain the perturbative expansion of the free energy on S4 for four dimensional Lagrangian N = 2 superconformal field theories, to all orders in the 't Hooft coupling, in the planar limit. We do so by using supersymmetric localization, after rewriting the 1-loop factor as an effective action involving an infinite number of single and double trace terms. The answer we obtain is purely combinatorial, and involves a sum over tree graphs. We also apply these methods to the perturbative expansion of the free energy at finite N , and to the computation of the vacuum expectation value of the 1/2 BPS circular Wilson loop, which in the planar limit involves a sum over rooted tree graphs

Energy Loss of an Infinitely Massive Half-Bogomol'nyi-Prasad-Sommerfeld Particle by Radiation to All Orders in 1/N

We use the AdS/CFT correspondence to compute the energy radiated by an infinitely massive half-Bogomol'nyi-Prasad-Sommerfeld particle charged under N = 4 super Yang-Mills theory, transforming in the symmetric or antisymmetric representation of the gauge group, and moving in the vacuum, to all orders in 1 / N and for large 't Hooft coupling. For the antisymmetric case we consider D 5 -branes reaching the boundary of five-dimensional anti-de Sitter space ( AdS 5 ) at arbitrary timelike trajectories, while for the symmetric case, we consider a D 3 -brane in AdS 5 that reaches the boundary at a hyperbola. We compare our results to the one obtained for the fundamental representation, deduced by considering a string in AdS 5

Energy Loss of an Infinitely Massive Half-Bogomol'nyi-Prasad-Sommerfeld Particle by Radiation to All Orders in 1/N

We use the AdS/CFT correspondence to compute the energy radiated by an infinitely massive half-Bogomol'nyi-Prasad-Sommerfeld particle charged under N = 4 super Yang-Mills theory, transforming in the symmetric or antisymmetric representation of the gauge group, and moving in the vacuum, to all orders in 1 / N and for large 't Hooft coupling. For the antisymmetric case we consider D 5 -branes reaching the boundary of five-dimensional anti-de Sitter space ( AdS 5 ) at arbitrary timelike trajectories, while for the symmetric case, we consider a D 3 -brane in AdS 5 that reaches the boundary at a hyperbola. We compare our results to the one obtained for the fundamental representation, deduced by considering a string in AdS 5

Probing N=2 superconformal field theories with localization

We use supersymmetric localization to study probes of four dimensional Lagrangian N=2 superconformal field theories. We first derive a unique equation for the eigenvalue density of these theories. We observe that these theories have a Wigner eigenvalue density precisely when they satisfy a necessary condition for having a holographic dual with a sensible higher-derivative expansion. We then compute in the saddle-point approximation the vacuum expectation value of 1/2-BPS circular Wilson loops, and the two-point functions of these Wilson loops with the Lagrangian density and with the stress-energy tensor. This last computation also provides the corresponding Bremsstrahlung functions and entanglement entropies. As expected, whenever a finite fraction of the matter is in the fundamental representation, the results are drastically different from those of N=4 supersymmetric Yang-Mills theory

Exact bremsstrahlung function in N=2 superconformal field theories

We propose an exact formula for the energy radiated by an accelerating quark in N = 2 superconformal theories in four dimensions. This formula reproduces the known bremsstrahlung function for N = 4 theories and provides a prediction for all the perturbative and instanton corrections in N = 2 theories. We perform a perturbative check of our proposal up to three loops

Exact bremsstrahlung function in N=2 superconformal field theories

We propose an exact formula for the energy radiated by an accelerating quark in N = 2 superconformal theories in four dimensions. This formula reproduces the known bremsstrahlung function for N = 4 theories and provides a prediction for all the perturbative and instanton corrections in N = 2 theories. We perform a perturbative check of our proposal up to three loops