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Title: Scattering forms and the positive geometry of kinematics, color and the worldsheet

Journal Article · · Journal of High Energy Physics (Online)
 [1];  [2];  [3];  [4]
  1. Inst. for Advanced Study, Princeton, NJ (United States). School of Natural Sciences
  2. Princeton Univ., NJ (United States). Dept. of Physics
  3. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Theoretical Physics, Key Lab. of Theoretical Physics; Univ. of Chinese Academy of Sciences, Beijing (China)
  4. Tsinghua Univ., Beijing (China). Inst. for Advanced Study; Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Theoretical Physics, Key Lab. of Theoretical Physics

The search for a theory of the S-Matrix over the past five decades has revealed surprising geometric structures underlying scattering amplitudes ranging from the string worldsheet to the amplituhedron, but these are all geometries in auxiliary spaces as opposed to the kinematical space where amplitudes actually live. Motivated by recent advances providing a reformulation of the amplituhedron and planar N = 4 SYM amplitudes directly in kinematic space, we propose a novel geometric understanding of amplitudes in more general theories. The key idea is to think of amplitudes not as functions, but rather as differential forms on kinematic space. We explore the resulting picture for a wide range of massless theories in general spacetime dimensions. For the bi-adjoint Φ3 scalar theory, we establish a direct connection between its “scattering form” and a classic polytope — the associahedron — known to mathematicians since the 1960’s. We find an associahedron living naturally in kinematic space, and the tree level amplitude is simply the “canonical form” associated with this “positive geometry”. Fundamental physical properties such as locality and unitarity, as well as novel “soft” limits, are fully determined by the combinatorial geometry of this polytope. Furthermore, the moduli space for the open string worldsheet has also long been recognized as an associahedron. We show that the scattering equations act as a diffeomorphism between the interior of this old “worldsheet associahedron” and the new “kinematic associahedron”, providing a geometric interpretation and simple conceptual derivation of the bi-adjoint CHY formula. We also find “scattering forms” on kinematic space for Yang-Mills theory and the Non-linear Sigma Model, which are dual to the fully color-dressed amplitudes despite having no explicit color factors. This is possible due to a remarkable fact—“Color is Kinematics”— whereby kinematic wedge products in the scattering forms satisfy the same Jacobi relations as color factors. Finally, all our scattering forms are well-defined on the projectivized kinematic space, a property which can be seen to provide a geometric origin for color-kinematics duality.

Research Organization:
Institute for Advanced Study, Princeton, NJ (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
Grant/Contract Number:
SC0009988
OSTI ID:
1502485
Journal Information:
Journal of High Energy Physics (Online), Vol. 2018, Issue 5; ISSN 1029-8479
Publisher:
Springer BerlinCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 133 works
Citation information provided by
Web of Science

References (51)

Combinatorics and topology of Kawai-Lewellen-Tye relations journal August 2017
Scattering in three dimensions from rational maps journal October 2013
Perturbative Gauge Theory as a String Theory in Twistor Space journal October 2004
Complete N-point superstring disk amplitude II. Amplitude and hypergeometric function structure journal August 2013
New color decompositions for gauge amplitudes at tree and loop level journal April 2000
Manifestly crossing-invariant parametrization of n-meson amplitude journal September 1969
Scattering of Massless Particles in Arbitrary Dimensions journal October 2014
Scattering equations: real solutions and particles on a line journal March 2017
Explicit BCJ numerators from pure spinors journal July 2011
The Amplituhedron journal October 2014
Scattering equations and matrices: from Einstein to Yang-Mills, DBI and NLSM journal July 2015
String Theory journal March 2011
New Relations for Gauge-Theory and Gravity Amplitudes at Loop Level journal April 2017
Grassmannian Geometry of Scattering Amplitudes book May 2016
Scattering of massless particles: scalars, gluons and gravitons journal July 2014
Properties of scattering forms and their relation to associahedra journal March 2018
New ambitwistor string theories journal November 2015
Perturbative Quantum Gravity as a Double Copy of Gauge Theory journal August 2010
Scattering Amplitudes from Intersection Theory journal April 2018
Positive geometries and canonical forms journal November 2017
The amplituhedron from momentum twistor diagrams journal February 2015
Eliminating spurious poles from gauge-theoretic amplitudes journal May 2013
Monoïdes préordonnés et chaînes de Malcev journal January 1951
A relation between tree amplitudes of closed and open strings journal May 1986
New BCJ representations for one-loop amplitudes in gauge theories and gravity journal May 2018
Multigluon cross sections and 5-jet production at hadron colliders journal January 1989
Loop Integrands for Scattering Amplitudes from the Riemann Sphere journal September 2015
Color Dual Form for Gauge-Theory Amplitudes journal August 2011
Multiple zeta values and periods of moduli spaces $\overline{\mathfrak{M}}_{0,n}$ journal January 2009
A duality for the S matrix journal March 2010
A current algebra for some gauge theory amplitudes journal November 1988
Unwinding the amplituhedron in binary journal January 2018
String theory journal July 2009
The irreducibility of the space of curves of given genus journal January 1969
String theory text January 2020
String theory journal September 1990
Eliminating spurious poles from gauge-theoretic amplitudes preprint January 2009
A Color Dual Form for Gauge-Theory Amplitudes text January 2011
Ambitwistor strings and the scattering equations text January 2013
Infinite Tension Limit of the Pure Spinor Superstring text January 2013
Loop Integrands for Scattering Amplitudes from the Riemann Sphere text January 2015
One-loop amplitudes on the Riemann sphere text January 2015
Unwinding the Amplituhedron in Binary text January 2017
Combinatorics and Topology of Kawai-Lewellen-Tye Relations text January 2017
Labelled tree graphs, Feynman diagrams and disk integrals text January 2017
Scattering Amplitudes from Intersection Theory text January 2017
Perturbative Gauge Theory As A String Theory In Twistor Space text January 2003
One-loop amplitudes on the Riemann sphere journal March 2016
Infrared behaviour of the one-loop scattering equations and supergravity integrands journal April 2015
Homotopy associativity of 𝐻-spaces. II journal January 1963
Two-Loop Scattering Amplitudes from the Riemann Sphere text January 2016

Cited By (34)

Δ-algebra and scattering amplitudes journal February 2019
On the kinematic algebra for BCJ numerators beyond the MHV sector journal November 2019
Hyperbolic geometry and amplituhedra in 1+2 dimensions journal August 2018
Scattering amplitudes as multi-particle higher-spin charges in the correspondence space journal August 2019
Accordiohedra as positive geometries for generic scalar field theories journal November 2019
Biadjoint scalar tree amplitudes and intersecting dual associahedra journal June 2018
Amplituhedron meets Jeffrey–Kirwan residue journal December 2018
String correlators: recursive expansion, integration-by-parts and scattering equations journal September 2019
Bootstrapping solutions of scattering equations journal February 2019
Double copy for massive quantum particles with spin text January 2019
String Amplitudes from Field-Theory Amplitudes and Vice Versa journal May 2019
Stokes polytopes: the positive geometry for ϕ4 interactions journal August 2019
Biadjoint scalar tree amplitudes and intersecting dual associahedra text January 2018
Scattering amplitudes as multi-particle higher-spin charges in the correspondence space text January 2018
Moduli Space of Paired Punctures, Cyclohedra and Particle Pairs on a Circle text January 2018
Double copy structure of CFT correlators text January 2018
All-loop cuts from the Amplituhedron text January 2019
Soft Bootstrap and Effective Field Theories text January 2019
On the kinematic algebra for BCJ numerators beyond the MHV sector text January 2019
String Correlators: Recursive Expansion, Integration-by-Parts and Scattering Equations text January 2019
UV considerations on scattering amplitudes in a web of theories text January 2019
On-shell electroweak sector and the Higgs mechanism journal August 2020
Cachazo-He-Yuan theory for several fields journal July 2020
Minkowski summands of cubes journal March 2022
Cluster Configuration Spaces of Finite Type journal October 2021
Cluster Algebras in Kinematic Space of Scattering Amplitudes preprint January 2017
Canonical Bases for Permutohedral Plates preprint January 2017
Generalized permutohedra in the kinematic space preprint January 2018
Aspects of Scattering Amplitudes and Moduli Space Localization text January 2019
The Duality Between Color and Kinematics and its Applications preprint January 2019
Exploring straight infinite Wilson lines in the Self Dual and the MHV Lagrangians text January 2020
Soft Gravity by Squaring Soft QED on the Celestial Sphere text January 2020
Gauge and Gravity Amplitudes on the Celestial Sphere text January 2020
Kinematic numerators from the worldsheet: cubic trees from labelled trees text January 2021

Figures / Tables (25)


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