scholarly journals One-loop string corrections to AdS amplitudes from CFT

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
J.M. Drummond ◽  
H. Paul
Keyword(s):  
Stress Tensor ◽  
Analytic Structure ◽  
Position Space ◽  
Yang Mills ◽  
String Corrections ◽  
The One ◽  
Loop Amplitudes

Abstract We consider α′ corrections to the one-loop four-point correlator of the stress- tensor multiplets in $$ \mathcal{N} $$ N = 4 super Yang-Mills at order 1/N4. Holographically, this is dual to string corrections of the one-loop supergravity amplitude on AdS5 × S5. While this correlator has been considered in Mellin space before, we derive the corresponding position space results, gaining new insights into the analytic structure of AdS loop amplitudes. Most notably, the presence of a transcendental weight three function involving new singularities is required, which has not appeared in the context of AdS amplitudes before. We thereby confirm the structure of string corrected one-loop Mellin amplitudes, and also provide new explicit results at orders in α′ not considered before.

scholarly journals The dimension-shift conjecture for one-loop amplitudes

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Ruth Britto ◽  
Guy R. Jehu ◽  
Andrea Orta
Keyword(s):  
Loop Structure ◽  
Yang Mills ◽  
Helicity Amplitudes ◽  
The One ◽  
Loop Amplitudes

Abstract A conjecture made by Bern, Dixon, Dunbar, and Kosower asserts a simple dimension shifting relationship between the one-loop structure of $$ \mathcal{N} $$ N = 4 MHV amplitudes and all-plus helicity amplitudes in pure Yang-Mills theory. We prove this conjecture to all orders in dimensional regularisation using unitarity cuts, and evaluate the form of these simplest one-loop amplitudes using a generalised D-dimensional unitarity technique which captures the full amplitude to all multiplicities.

scholarly journals The integrable (hyper)eclectic spin chain

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Changrim Ahn ◽  
Matthias Staudacher
Keyword(s):  
Spin Chain ◽  
Nearest Neighbor ◽  
Inverse Scattering Method ◽  
Spin Chains ◽  
Scattering Method ◽  
Yang Mills ◽  
Deformation Parameters ◽  
Dilatation Operator ◽  
The One ◽  
State Spin

Abstract We refine the notion of eclectic spin chains introduced in [1] by including a maximal number of deformation parameters. These models are integrable, nearest-neighbor n-state spin chains with exceedingly simple non-hermitian Hamiltonians. They turn out to be non-diagonalizable in the multiparticle sector (n > 2), where their “spectrum” consists of an intricate collection of Jordan blocks of arbitrary size and multiplicity. We show how and why the quantum inverse scattering method, sought to be universally applicable to integrable nearest-neighbor spin chains, essentially fails to reproduce the details of this spectrum. We then provide, for n=3, detailed evidence by a variety of analytical and numerical techniques that the spectrum is not “random”, but instead shows surprisingly subtle and regular patterns that moreover exhibit universality for generic deformation parameters. We also introduce a new model, the hypereclectic spin chain, where all parameters are zero except for one. Despite the extreme simplicity of its Hamiltonian, it still seems to reproduce the above “generic” spectra as a subset of an even more intricate overall spectrum. Our models are inspired by parts of the one-loop dilatation operator of a strongly twisted, double-scaled deformation of $$ \mathcal{N} $$ N = 4 Super Yang-Mills Theory.

scholarly journals Loops in AdS: from the spectral representation to position space. Part II

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Dean Carmi
Keyword(s):  
Spectral Representation ◽  
Tree Level ◽  
Point Function ◽  
Position Space ◽  
Gross Neveu Model ◽  
Loop Amplitudes

Abstract We continue the study of AdS loop amplitudes in the spectral representation and in position space. We compute the finite coupling 4-point function in position space for the large-N conformal Gross Neveu model on AdS3. The resummation of loop bubble diagrams gives a result proportional to a tree-level contact diagram. We show that certain families of fermionic Witten diagrams can be easily computed from their companion scalar diagrams. Thus, many of the results and identities of [1] are extended to the case of external fermions. We derive a spectral representation for ladder diagrams in AdS. Finally, we compute various bulk 2-point correlators, extending the results of [1].

scholarly journals Two-loop rational terms in Yang-Mills theories

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Jean-Nicolas Lang ◽  
Stefano Pozzorini ◽  
Hantian Zhang ◽  
Max F. Zoller
Keyword(s):  
Scattering Amplitudes ◽  
Gauge Theories ◽  
A Posteriori ◽  
Four Dimensions ◽  
Yang Mills ◽  
General Properties ◽  
Finite Set ◽  
Numerical Tools ◽  
Loop Amplitudes

Abstract Scattering amplitudes in D dimensions involve particular terms that originate from the interplay of UV poles with the (D − 4)-dimensional parts of loop numerators. Such contributions can be controlled through a finite set of process-independent rational counterterms, which make it possible to compute loop amplitudes with numerical tools that construct the loop numerators in four dimensions. Building on a recent study [1] of the general properties of two-loop rational counterterms, in this paper we investigate their dependence on the choice of renormalisation scheme. We identify a nontrivial form of scheme dependence, which originates from the interplay of mass and field renormalisation with the (D−4)-dimensional parts of loop numerators, and we show that it can be controlled through a new kind of one-loop counterterms. This guarantees that the two-loop rational counterterms for a given renormalisable theory can be derived once and for all in terms of generic renormalisation constants, which can be adapted a posteriori to any scheme. Using this approach, we present the first calculation of the full set of two-loop rational counterterms in Yang-Mills theories. The results are applicable to SU(N) and U(1) gauge theories coupled to nf fermions with arbitrary masses.

scholarly journals MHV one-loop amplitudes in Yang-Mills from generalised unitarity

2008 ◽  
Vol 2008 (11) ◽  
pp. 078-078 ◽  
Author(s):  
Andreas Brandhuber ◽  
Massimiliano Vincon
Keyword(s):  
Yang Mills ◽  
Loop Amplitudes

scholarly journals Kerr-Newman stress-tensor from minimal coupling

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Ming-Zhi Chung ◽  
Yu-tin Huang ◽  
Jung-Wook Kim
Keyword(s):  
Form Factor ◽  
Stress Tensor ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Minimal Coupling ◽  
Massive Spin ◽  
Stress Energy ◽  
Newman Black Hole ◽  
Higher Spin ◽  
The One

Abstract In this paper, we demonstrate that at leading order in post Minkowskian (PM) expansion, the stress-energy tensor of Kerr-Newman black hole can be recovered to all orders in spin from three sets of minimal coupling: the electric and gravitational minimal coupling for higher-spin particles, and the “minimal coupling” for massive spin-2 decay. These couplings are uniquely defined from kinematic consideration alone. This is shown by extracting the classical piece of the one-loop stress-energy tensor form factor, which we provide a basis that is valid to all orders in spin. The 1 PM stress tensor, and the metric in the harmonic gauge, is then recovered from the classical spin limit of the form factor.

scholarly journals NONCOMMUTATIVE U(1) SUPER-YANG–MILLS THEORY: PERTURBATIVE SELF-ENERGY CORRECTIONS

2004 ◽  
Vol 19 (25) ◽  
pp. 4231-4249 ◽  
Author(s):  
A. A. BICHL ◽  
M. ERTL ◽  
A. GERHOLD ◽  
J. M. GRIMSTRUP ◽  
L. POPP ◽  
...  
Keyword(s):  
Power Counting ◽  
The Self ◽  
Field Theories ◽  
Yang Mills ◽  
Self Energy ◽  
Supersymmetric Field Theories ◽  
Crucial Feature ◽  
The One ◽  
Infrared Divergences ◽  
Super Yang Mills Theory

The quantization of the noncommutative [Formula: see text], U(1) super-Yang–Mills action is performed in the superfield formalism. We calculate the one-loop corrections to the self-energy of the vector superfield. Although the power-counting theorem predicts quadratic ultraviolet and infrared divergences, there are actually only logarithmic UV and IR divergences, which is a crucial feature of noncommutative supersymmetric field theories.

scholarly journals Paramagnetic versus Diamagnetic Interaction in the SU(2) Higgs Model

Symmetry ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1237
Author(s):  
Dmitry Antonov
Keyword(s):  
Gauge Boson ◽  
Effective Action ◽  
Dimensional Reduction ◽  
Higgs Model ◽  
Analytic Calculation ◽  
Standard Result ◽  
Correlation Lengths ◽  
Yang Mills ◽  
Diamagnetic Contribution ◽  
The One

We present an analytic calculation of the paramagnetic and diamagnetic contributions to the one-loop effective action in the SU(2) Higgs model. The paramagnetic contribution is produced by the gauge boson, while the diamagnetic contribution is produced by the gauge boson and the ghost. In the limit, where these particles are massless, the standard result of - 12 for the ratio of the paramagnetic to the diamagnetic contribution is reproduced. If the mass of the gauge boson and the ghost become much larger than the inverse vacuum correlation lengths of the Yang–Mills vacuum, the value of the ratio goes to - 8 . We also find that the same values of the ratio are achieved in the deconfinement phase of the model, up to the temperatures at which the dimensional reduction occurs.

scholarly journals 4D N = 1 SYM supercurrent on the lattice in terms of the gradient flow

2018 ◽  
Vol 175 ◽  
pp. 11014
Author(s):  
Kenji Hieda ◽  
Aya Kasai ◽  
Hiroki Makino ◽  
Hiroshi Suzuki
Keyword(s):  
Gradient Flow ◽  
Independent Manner ◽  
Yang Mills ◽  
Loop Level ◽  
Lattice Regularization ◽  
The One ◽  
Noether Current ◽  
Super Yang Mills Theory

The gradient flow [1–5] gives rise to a versatile method to construct renor-malized composite operators in a regularization-independent manner. By adopting this method, the authors of Refs. [6–9] obtained the expression of Noether currents on the lattice in the cases where the associated symmetries are broken by lattice regularization. We apply the same method to the Noether current associated with supersymmetry, i.e., the supercurrent. We consider the 4D N = 1 super Yang–Mills theory and calculate the renormalized supercurrent in the one-loop level in the Wess–Zumino gauge. We then re-express this supercurrent in terms of the flowed gauge and flowed gaugino fields [10].

DIVERGENT SURFACE TERMS IN NON-COVARIANT GAUGES

1991 ◽  
Vol 06 (24) ◽  
pp. 2217-2227
Author(s):  
R. B. MANN ◽  
T. RUDY
Keyword(s):  
Divergent Part ◽  
Surface Term ◽  
Yang Mills ◽  
Self Energy ◽  
Covariant Gauge ◽  
The Difference ◽  
The One

Using Leibbrandt's general prescription for regularizing (n · q)−1 poles in momentum intergrals in axial-type non-covariant gauges we show that the difference between two linearly divergent integrals which arise in such gauges yield a surface term which is logarithmically divergent. The form of divergence of this term is shown to be independent of the choice of non-covariant gauge. We show that such a term modifies the expression for the one-loop Yang–Mills self-energy evaluated using a cutoff scheme of adding to it a divergent part.

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