514 research outputs found
Umkehr Maps Patched via the Compactified Cleavage Operad
Via a compactification of the cleavage operad, we describe two actions on the
mapping spaces from spheres into compact, oriented manifolds. The map from the
compactified version of the cleavage operad provides a version of intersection
theory along the underlying base manifold lifted to the mapping space. The
other action map only works for the uncompactified cleavage operad, and gives a
homotopy theoretic version of higher dimensional string topology.Comment: This paper is under revision since there is a mistake not taking
twistings into account. An upcoming paper with a different scope solves this
problem in a geometric fashion. The statements on the compactifications in
this paper will be reformulated accordingl
The Two-Loop Symbol of all Multi-Regge Regions
We study the symbol of the two-loop n-gluon MHV amplitude for all Mandelstam
regions in multi-Regge kinematics in N=4 super Yang-Mills theory. While the
number of distinct Mandelstam regions grows exponentially with n, the increase
of independent symbols turns out to be merely quadratic. We uncover how to
construct the symbols for any number of external gluons from just two building
blocks which are naturally associated with the six- and seven-gluon amplitude,
respectively. The second building block is entirely new, and in addition to its
symbol, we also construct a prototype function that correctly reproduces all
terms of maximal functional transcendentality.Comment: 20 pages, v2: include details on functions f and g, make appendix
consistent with main text, typesetting (published version
Symmetries of Tree-level Scattering Amplitudes in N=6 Superconformal Chern-Simons Theory
Constraints of the osp(6|4) symmetry on tree-level scattering amplitudes in
N=6 superconformal Chern-Simons theory are derived. Supplemented by Feynman
diagram calculations, solutions to these constraints, namely the four- and
six-point superamplitudes, are presented and shown to be invariant under
Yangian symmetry. This introduces integrability into the amplitude sector of
the theory.Comment: 50 pages. v2, v3: References added, minor correction
New Relations for Three-Dimensional Supersymmetric Scattering Amplitudes
We provide evidence for a duality between color and kinematics in
three-dimensional supersymmetric Chern-Simons matter theories. We show that the
six-point amplitude in the maximally supersymmetric, N=8, theory can be
arranged so that the kinematic factors satisfy the fundamental identity of
three-algebras. We further show that the four- and six-point N=8 amplitudes can
be "squared" into the amplitudes of N=16 three-dimensional supergravity, thus
providing evidence for a hidden three-algebra structure in the dynamics of the
supergravity.Comment: 8 pages, 2 figure
Integrable Amplitude Deformations for N=4 Super Yang-Mills and ABJM Theory
We study Yangian-invariant deformations of scattering amplitudes in 4d N=4
supersymmetric Yang-Mills theory and 3d N=6 Aharony-Bergman-Jafferis-Maldacena
(ABJM) theory. In particular, we obtain the deformed Grassmannian integral for
4d N=4 super Yang-Mills theory, both in momentum and momentum-twistor space.
For 3d ABJM theory, we initiate the study of deformed scattering amplitudes. We
investigate general deformations of on-shell diagrams, and find the deformed
Grassmannian integral for this theory. We furthermore introduce the algebraic
R-matrix construction of deformed Yangian invariants for ABJM theory.Comment: 39 pages, 9 figures; v2: references added, typos fixed, section 3.4
improved, published versio
The cleavage operad and string topology of higher dimension
[no abstract available
Handling Handles: Nonplanar Integrability in Supersymmetric Yang-Mills Theory
We propose an integrability setup for the computation of correlation
functions of gauge-invariant operators in supersymmetric
Yang-Mills theory at higher orders in the large genus expansion
and at any order in the 't Hooft coupling . In
this multi-step proposal, one polygonizes the string worldsheet in all possible
ways, hexagonalizes all resulting polygons, and sprinkles mirror particles over
all hexagon junctions to obtain the full correlator. We test our
integrability-based conjecture against a non-planar four-point correlator of
large half-BPS operators at one and two loops.Comment: 6 pages, 4 figures; v2: updated references, typos, minor improvements
(published version
Following Strain-Induced Mosaicity Changes of Ferroelectric Thin Films by Ultrafast Reciprocal Space Mapping
We investigate coherent phonon propagation in a thin film of ferroelectric
PbZr0.2Ti0.8O3 (PZT) by ultrafast x-ray diffraction (UXRD) experiments, which
are analyzed as time-resolved reciprocal space mapping (RSM) in order to
observe the in- and out-of-plane structural dynamics simultaneously. The mosaic
structure of the PZT leads to a coupling of the excited out-of-plane expansion
to in-plane lattice dynamics on a picosecond timescale, which is not observed
for out-of-plane compression.Comment: 5 pages, 4 figure
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