1,800 research outputs found
BPS -branes in Dual to Loop Operators
In this paper, we first compute the Killing spinors of and its certain orbifolds. Based on this, two classes of -brane
solutions are found. The first class of solutions includes -branes dual to
Wilson loops in the fundamental representation as special cases. The second
class includes the candidates of the holographic description of vortex loops in
the dual field theories.Comment: v6, typoes fixed, 14 pages, no figure
Comments on Two-Loop Four-Particle Amplitude in Superstring Theory
It is shown that the four-particle amplitude of superstring theory at two
loops obtained in [1,2] is equivalent to the previously obtained results in
[3,4,5]. Here the symmetry in hyperelliptic Riemann surface plays
an important role in the proof.Comment: 10 pages, Latex fil
Two-Loop Superstrings in Hyperelliptic Language III: the Four-Particle Amplitude
We compute explicitly the four-particle amplitude in superstring theories by
using the hyperelliptic language and the newly obtained chiral measure of
D'Hoker and Phong. Although the algebra of the intermediate steps is a little
bit involved, we obtain a quite simple expression for the four-particle
amplitude. As expected, the integrand is independent of all the insertion
points. As an application of the obtained result, we show that the perturbative
correction to the term in type II superstring theories is vanishing
point-wise in (even) moduli space at two loops.Comment: v1, LaTex file, 33 pages; v2, 34 pages, add references and minor
correction
New electromagnetic memories and soft photon theorems
In this paper, we present a new type of electromagnetic memory. It is a
`magnetic' type, or B mode, radiation memory effect. Rather than a residual
velocity, we find a position displacement of a charged particle induced by the
B mode radiation with memory. We find two types of electromagnetic displacement
(ordinary and null). We also show that the null electromagnetic memory formulas
are nothing but a Fourier transformation of soft photon theorems.Comment: v2: interpretation improved and typos fixed, refs adde
Scattering Equations, Twistor-string Formulas and Double-soft Limits in Four Dimensions
We study scattering equations and formulas for tree amplitudes of various
theories in four dimensions, in terms of spinor helicity variables and on-shell
superspace for supersymmetric theories. As originally obtained in Witten's
twistor string theory and other twistor-string models, the equations can take
either polynomial or rational forms, and we clarify the simple relation between
them. We present new, four-dimensional formulas for all tree amplitudes in the
non-linear sigma model, a special Galileon theory and the maximally
supersymmetric completion of the Dirac-Born-Infeld theory. Furthermore, we
apply the formulas to study various double-soft theorems in these theories,
including the emissions of a pair of soft photons, fermions and scalars for
super-amplitudes in super-DBI theory.Comment: 22 pages, 2 tables; v2: ref added, minor typos fixe
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