scholarly journals PERTURBATIVE ANALYSIS OF THE SEIBERG–WITTEN MAP

2002 ◽  
Vol 17 (16) ◽  
pp. 2219-2231 ◽  
Author(s):  
A. A. BICHL ◽  
J. M. GRIMSTRUP ◽  
L. POPP ◽  
M. SCHWEDA ◽  
R. WULKENHAAR
Keyword(s):  
Loop Correction ◽  
Yang Mills ◽  
Energy Correction ◽  
Self Energy ◽  
The One ◽  
Field Redefinition

We investigate the quantization of the θ-expanded noncommutative U(1) Yang–Mills action, obtained via the Seiberg–Witten map. The one-loop self-energy correction is gauge-independent. In a further paper, hep-th/0104097, we have shown that the loop correction may be renormalized via an unphysical field redefinition.

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.

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.

One-loop self-energy correction to the bound-electron g factor

2002 ◽  
Vol 80 (11) ◽  
pp. 1249-1254 ◽  
Author(s):  
V A Yerokhin ◽  
P Indelicato ◽  
V M Shabaev
Keyword(s):  
Numerical Evaluation ◽  
G Factor ◽  
Energy Correction ◽  
Self Energy ◽  
The One ◽  
Bound Electron

Accurate numerical evaluation of the one-loop self-energy correction to the 1s-electron g factor in H-like ions is presented to all orders in the parameter Zα. This calculation significantly improves the accuracy of theoretical values of the corresponding g factor in low- and medium-Z ions.

scholarly journals RADIATIVE CORRECTIONS TO THE PRESSURE AND THE ONE-LOOP POLARIZATION TENSOR OF MASSLESS MODES IN SU(2) YANG–MILLS THERMODYNAMICS

2007 ◽  
Vol 22 (06) ◽  
pp. 1213-1237 ◽  
Author(s):  
MARKUS SCHWARZ ◽  
RALF HOFMANN ◽  
FRANCESCO GIACOSA
Keyword(s):  
Atomic Hydrogen ◽  
Black Body ◽  
Coulomb Gauge ◽  
Polarization Tensor ◽  
Radiative Corrections ◽  
Loop Correction ◽  
Yang Mills ◽  
Massless Mode ◽  
The Stability ◽  
The One

We compute the one-loop polarization tensor Π for the on-shell, massless mode in a thermalized SU(2) Yang–Mills theory being in its deconfining phase. Postulating that [Formula: see text], we discuss Π's effect on the low-momentum part of the black-body spectrum at temperatures ~2,…,4 T CMB where T CMB ~ 2.73 K . A table-top experiment is proposed to test the above postulate. As an application, we point out a possible connection with the stability of dilute, cold, and old innergalactic atomic hydrogen clouds. We also compute the two-loop correction to the pressure arising from the instantaneous massless mode in unitary-Coulomb gauge, which formerly was neglected, and present improved estimates for subdominant corrections.

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 Master integrals for bipartite cuts of three-loop photon self energy

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
R. N. Lee ◽  
A. I. Onishchenko
Keyword(s):  
Spectral Density ◽  
High Energy ◽  
Elliptic Integrals ◽  
Iterated Integrals ◽  
Self Energy ◽  
Complete Elliptic Integrals ◽  
The One

Abstract We calculate the master integrals for bipartite cuts of the three-loop propagator QED diagrams. These master integrals determine the spectral density of the photon self energy. Our results are expressed in terms of the iterated integrals, which, apart from the 4m cut (the cut of 4 massive lines), reduce to Goncharov’s polylogarithms. The master integrals for 4m cut have been calculated in our previous paper in terms of the one-fold integrals of harmonic polylogarithms and complete elliptic integrals. We provide the threshold and high-energy asymptotics of the master integrals found, including those for 4m cut.

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.

Infrared finiteness of the two-loop correction to the Chern–Simons term in the Yang–Mills–Chern–Simons theory

1995 ◽  
Vol 73 (5-6) ◽  
pp. 344-348 ◽  
Author(s):  
Yeong-Chuan Kao ◽  
Hsiang-Nan Li
Keyword(s):  
Effective Action ◽  
Background Field ◽  
Landau Gauge ◽  
Quantum Corrections ◽  
Simons Theory ◽  
Loop Correction ◽  
Loop Contribution ◽  
Yang Mills ◽  
Chern Simons ◽  
Chern Simons Theory

We show that the two-loop contribution to the coefficient of the Chern–Simons term in the effective action of the Yang–Mills–Chern–Simons theory is infrared finite in the background field Landau gauge. We also discuss the difficulties in verifying the conjecture, due to topological considerations, that there are no more quantum corrections to the Chern–Simons term other than the well-known one-loop shift of the coefficient.

RENORMALIZATION OF FERMI VELOCITY IN A COMPOSITE TWO DIMENSIONAL ELECTRON GAS

1993 ◽  
Vol 07 (01n03) ◽  
pp. 87-94 ◽  
Author(s):  
M. WEGER ◽  
L. BURLACHKOV
Keyword(s):  
Electron Gas ◽  
Fermi Velocity ◽  
Bohr Radius ◽  
Dimensional Electron ◽  
Temperature Dependent ◽  
Two Dimensional Electron Gas ◽  
Self Energy ◽  
2D System ◽  
Dimensional Electron Gas ◽  
The One

We calculate the self-energy Σ(k, ω) of an electron gas with a Coulomb interaction in a composite 2D system, consisting of metallic layers of thickness d ≳ a 0, where a 0 = ħ2∊1/ me 2 is the Bohr radius, separated by layers with a dielectric constant ∊2 and a lattice constant c perpendicular to the planes. The behavior of the electron gas is determined by the dimensionless parameters k F a 0 and k F c ∊2/∊1. We find that when ∊2/∊1 is large (≈5 or more), the velocity v(k) becomes strongly k-dependent near k F , and v ( k F ) is enhanced by a factor of 5-10. This behavior is similar to the one found by Lindhard in 1954 for an unscreened electron gas; however here we take screening into account. The peak in v(k) is very sharp (δ k/k F is a few percent) and becomes sharper as ∊2/∊1 increases. This velocity renormalization has dramatic effects on the transport properties; the conductivity at low T increases like the square of the velocity renormalization and the resistivity due to elastic scattering becomes temperature dependent, increasing approximately linearly with T. For scattering by phonons, ρ ∝ T 2. Preliminary measurements suggest an increase in v k in YBCO very close to k F .

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