Electromagnetic and color memory in even dimensions

Abstract

We explore memory effects associated to both Abelian and non-Abelian radiation getting to null infinity, in arbitrary even spacetime dimensions. Together with classical memories, linear and non-linear, amounting to permanent kicks in the velocity of the probes, we also discuss the higher-dimensional counterparts of quantum memory effects, manifesting themselves in modifications of the relative phases describing a configuration of several probes. In addition, we analyse the structure of the asymptotic symmetries of Maxwell's theory in any dimension, both even and odd, in the Lorenz gauge.

Classical Yang-Mills observables from amplitudes

“…Although our motivation lies in gravitational dynamics, classical YM theory is also important in other contexts. Its asymptotic symmetry group has recently received intense study both for its own intrinsic interest but also as a toy model for the asymptotic symmetry group of gravity [106][107][108][109][110][111][112]. The radiation of colour charge of interest to us is also important in that context.…”

“…Of course, it is also possible to derive this expression directly from the Noether charge for vector fields in the adjoint representation, given in equation (5.15), in close analogy to our discussion in sections 2.1 and 2.2. This adjoint colour charge is of interest elsewhere in the literature since it plays a role in the physics of YM theory at asymptotic infinity [106][107][108][109][110][111][112]. In this connection, the nature of the final state of the radiation is relevant [111].…”

Asymptotic symmetries of Yang-Mills fields in Hamiltonian formulation

“…Although the first studies concerning general relativity at null infinity appeared more than half a century ago [1][2][3], the subject have been revitalised more recently after it has been conjectured that it may be related to the solution of the long-standing information-loss paradox [4] and it has been a very active area of research in the last years. Several studies have already analysed many aspects of the topic, such as the situation at null infinity and the connection to soft theorems [5][6][7][8][9][10][11][12][13][14], the relation with the potentially-detectable memory effect [15][16][17], the asymptotic (A)dS case [18,19], and the situation at spatial infinity [20][21][22][23][24][25]. It is in particular the latter that deeply connects with the present paper.…”

Source and response soft charges for Maxwell theory on AdSd

“…We also discuss how the AdS d isometry charges act on our soft mode phase space. In section 7, we show how our results on AdS d and those studied in the literature for Maxwell theory on flat space [19][20][21][22][23][24][25][26][27] could be related to each other through an AdS (large radius) flat space limit. In particular, we show that only the source boundary gauge transformations and the associated soft charges survive the limit and the response charges become subdominant and do not appear in the limit.…”