Next to subleading soft-graviton theorem in arbitrary dimensions

Abstract:The subleading corrections to factorization theorems for soft bremsstrahlung in nonabelian gauge theories and gravity are investigated in the case of a five point amplitude with four scalars. Building on recent results, we write the action of the angular momentum operators on scattering amplitudes as derivatives with respect to the Mandelstam invariants to uncover a double copy structure in the contribution of the soft graviton to the amplitude, both in the leading term and the first correction. Using our approach, we study Gribov's theorem as extended to nonabelian gauge theories and gravity by Lipatov, and find that subleading corrections can be obtained from those to Low's theorem by dropping the terms with derivatives with respect to the center-of-mass energy, which are suppressed at high energies. In this case, the emitted gravitons are not necessarily soft.

“…It has been argued that this result is not renormalized [8,9]. Generalizations of this new soft-graviton theorem to arbitrary dimensions were studied in [10][11][12].…”

Section: Jhep03(2015)070mentioning

confidence: 99%

The double copy structure of soft gravitons

Vera

Vázquez-Mozo

2015

“…Analytic solutions of the scattering equations have been investigated in [12][13][14] and extensions to the scattering of massive particles are discussed in [7,15]. In addition, there are interesting connections with string theory [16][17][18][19][20][21] and -of course -gravity [22][23][24][25][26][27].…”

Section: Jhep03(2015)141mentioning

confidence: 99%

Fermions and the scattering equations

Weinzierl

2015

This paper investigates how tree-level amplitudes with massless quarks, gluons and/or massless scalars transforming under a single copy of the gauge group can be expressed in the context of the scattering equations as a sum over the inequivalent solutions of the scattering equations. In the case where the amplitudes satisfy cyclic invariance, KK-and BCJ-relations the only modification is the generalisation of the permutation invariant function E(z, p, ε). We present a method to compute the modifiedÊ(z, p, ε). The most important examples are tree amplitudes in N = 4 SYM and QCD amplitudes with one quark-antiquark pair and an arbitrary number of gluons. QCD amplitudes with two or more quark-antiquark pairs do not satisfy the BCJ-relations and require in addition a generalisation of the Parke-Taylor factors C σ (z). The simplest case of the QCD tree-level four-point amplitude with two quark-antiquark pairs is discussed explicitly.

“…. , n), (1.3) where the leading and subleading soft factors are given by 4) with ε sν denoting the polarization of the soft gluon and a ∼ s meaning partial a is next to soft particle s. Many related studies have been achieved including the soft limits from Poincare symmetry and gauge invariance [18,19], Feynman diagram approach [20], conformal symmetry approach to the soft limits in Yang-Mills theory [21], the soft limit in arbitrary dimension [22][23][24][25], loop correction of the soft limit [26][27][28]30], string-theory approach to the soft limit [29,30] and ambitwistor string approach [31,32]. In physics, it is very fruitful to study same thing from various angles because it will deepen our understanding and reveal many hidden relations.…”

Section: Jhep11(2014)090mentioning

confidence: 99%

Note on soft graviton theorem by KLT relation

Feng

et al. 2014

Recently, new soft graviton theorem proposed by Cachazo and Strominger has inspired a lot of works. In this note, we use the KLT-formula to investigate the theorem. We have shown how the soft behavior of color ordered Yang-Mills amplitudes can be combined with KLT relation to give the soft behavior of gravity amplitudes. As a byproduct, we find two nontrivial identities of the KLT momentum kernel must hold.