scholarly journals Building bases of loop integrands

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Jacob L. Bourjaily ◽  
Enrico Herrmann ◽  
Cameron Langer ◽  
Jaroslav Trnka
Keyword(s):  
Scattering Amplitude ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Arbitrary Mass ◽  
Yang Mills ◽  
Graph Theoretic ◽  
Planar Limit ◽  
The Standard Model ◽  
Definition Of ◽  
Massless Quantum

Abstract We describe a systematic approach to the construction of loop-integrand bases at arbitrary loop-order, sufficient for the representation of general quantum field theories. We provide a graph-theoretic definition of ‘power-counting’ for multi-loop integrands beyond the planar limit, and show how this can be used to organize bases according to ultraviolet behavior. This allows amplitude integrands to be constructed iteratively. We illustrate these ideas with concrete applications. In particular, we describe complete integrand bases at two loops sufficient to represent arbitrary-multiplicity amplitudes in four (or fewer) dimensions in any massless quantum field theory with the ultraviolet behavior of the Standard Model or better. We also comment on possible extensions of our framework to arbitrary (including regulated) numbers of dimensions, and to theories with arbitrary mass spectra and charges. At three loops, we describe a basis sufficient to capture all ‘leading-(transcendental-)weight’ contributions of any four-dimensional quantum theory; for maximally supersymmetric Yang-Mills theory, this basis should be sufficient to represent all scattering amplitude integrands in the theory — for generic helicities and arbitrary multiplicity.

scholarly journals Quantum Theory Without Classical Time: Octonions, and a Theoretical Derivation of the Fine Structure Constant 1/137

2021 ◽  
Author(s):  
TEJINDER P. SINGH
Keyword(s):  
Fine Structure ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Model Parameters ◽  
Quantum Field ◽  
Theoretical Derivation ◽  
Yang Mills ◽  
The Standard Model ◽  
Definition Of ◽  
Spacetime Theory

There must exist a reformulation of quantum field theory which does not refer to classical time. We propose a pre-quantum, pre-spacetime theory, which is a matrix-valued Lagrangian dynamics for gravity, Yang-Mills fields, and fermions. The definition of spin in this theory leads us to an eight dimensional octonionic space-time. The algebra of the octonions reveals the standard model; model parameters are determined by roots of the cubic characteristic equation of the exceptional Jordan algebra. We derive the asymptotic low energy value 1/137 of the fine structure constant, and predict the existence of universally interacting spin one Lorentz bosons, which replace the hypothesised graviton. Gravity is not to be quantized, but is an emergent four-dimensional classical phenomenon, precipitated by the spontaneous localisation of highly entangled fermions.

scholarly journals Quantum theory without classical time: Octonions, and a theoretical derivation of the Fine Structure Constant 1/137

2021 ◽  
pp. 2142010
Author(s):  
Tejinder P. Singh
Keyword(s):  
Fine Structure ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Model Parameters ◽  
Quantum Field ◽  
Theoretical Derivation ◽  
Yang Mills ◽  
The Standard Model ◽  
Definition Of ◽  
Spacetime Theory

There must exist a reformulation of quantum field theory which does not refer to classical time. We propose a pre-quantum, pre-spacetime theory, which is a matrix-valued Lagrangian dynamics for gravity, Yang–Mills fields, and fermions. The definition of spin in this theory leads us to an eight-dimensional octonionic spacetime. The algebra of the octonions reveals the standard model; model parameters are determined by roots of the cubic characteristic equation of the exceptional Jordan algebra. We derive the asymptotic low-energy value 1/137 of the fine structure constant, and predict the existence of universally interacting spin one Lorentz bosons, which replace the hypothesised graviton. Gravity is not to be quantized, but is an emergent four-dimensional classical phenomenon, precipitated by the spontaneous localisation of highly entangled fermions.

scholarly journals THE RELATIONS BETWEEN GENERALIZED FIELDS AND SUPERFIELDS FORMALISMS OF THE BATALIN–VILKOVISKY METHOD OF QUANTIZATION

2004 ◽  
Vol 19 (14) ◽  
pp. 2339-2353 ◽  
Author(s):  
ÖMER F. DAYI
Keyword(s):  
General Solution ◽  
Master Equation ◽  
Gauge Theories ◽  
Relativistic Particle ◽  
Field Theories ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Yang Mills ◽  
Topological Quantum ◽  
Topological Quantum Field Theories

A general solution of the Batalin–Vilkovisky master equation was formulated in terms of generalized fields. Recently, a superfields approach of obtaining solutions of the Batalin–Vilkovisky master equation is also established. Superfields formalism is usually applied to topological quantum field theories. However, generalized fields method is suitable to find solutions of the Batalin–Vilkovisky master equation either for topological quantum field theories or the usual gauge theories like Yang–Mills theory. We show that by truncating some components of superfields with appropriate actions, generalized fields formalism of the usual gauge theories result. We demonstrate that for some topological quantum field theories and the relativistic particle both of the methods possess the same field contents and yield similar results. Inspired by the observed relations, we give the solution of the BV master equation for on-shell N=1 supersymmetric Yang–Mills theory utilizing superfields.

The light-cone gauge

1986 ◽  
Vol 64 (5) ◽  
pp. 624-632 ◽  
Author(s):  
H. C. Lee
Keyword(s):  
Quantum Chromodynamics ◽  
Quantum Electrodynamics ◽  
Light Cone ◽  
Field Theories ◽  
Special Role ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Light Cone Gauge ◽  
Yang Mills ◽  
Kaluza Klein

Some aspects of recent development in the light-cone gauge and its special role in quantum-field theories are reviewed. Topics discussed include the two- and four-component formulations of the light-cone gauge, Slavnov–Taylor and Becchi– Rouet–Stora identities, quantum electrodynamics, quantum chromodynamics, renormalization of Yang–Mills theory and supersymmetric theory, gravity, and the quantum-induced compactification of Kaluza–Klein theories in the light-cone gauge.

⋆-cohomology, third type Chern character and anomalies in general translation-invariant noncommutative Yang–Mills

2021 ◽  
pp. 2150089
Author(s):  
Amir Abbass Varshovi
Keyword(s):  
Chern Character ◽  
Adjoint Action ◽  
Field Theories ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Translation Invariant ◽  
Yang Mills ◽  
Noncommutative Version ◽  
General Translation ◽  
Noncommutative Quantum

A representation of general translation-invariant star products ⋆ in the algebra of [Formula: see text] is introduced which results in the Moyal–Weyl–Wigner quantization. It provides a matrix model for general translation-invariant noncommutative quantum field theories in terms of the noncommutative calculus on differential graded algebras. Upon this machinery a cohomology theory, the so-called ⋆-cohomology, with groups [Formula: see text], [Formula: see text], is worked out which provides a cohomological framework to formulate general translation-invariant noncommutative quantum field theories based on the achievements for the commutative fields, and is comparable to the Seiberg–Witten map for the Moyal case. Employing the Chern–Weil theory via the integral classes of [Formula: see text] a noncommutative version of the Chern character is defined as an equivariant form which contains topological information about the corresponding translation-invariant noncommutative Yang–Mills theory. Thereby, we study the mentioned Yang–Mills theories with three types of actions of the gauge fields on the spinors, the ordinary, the inverse, and the adjoint action, and then some exact solutions for their anomalous behaviors are worked out via employing the homotopic correlation on the integral classes of ⋆-cohomology. Finally, the corresponding consistent anomalies are also derived from this topological Chern character in the ⋆-cohomology.

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