scholarly journals VANISHING OF THE BARE COUPLING IN FOUR DIMENSIONS

2003 ◽  
Vol 18 (13) ◽  
pp. 2395-2401 ◽  
Author(s):  
V. ELIAS ◽  
D. G. C. MCKEON

We examine two restructurings of the series relationship between the bare and renormalized coupling constant in dimensional regularization. In one of these restructurings, we are able to demonstrate via all-orders summation of leading and successive ∊ = 0 (dimensionality = 4) poles that the bare coupling vanishes in the dimension-4 limit.

2018 ◽  
Vol 33 (26) ◽  
pp. 1830024 ◽  
Author(s):  
Jean-François Mathiot

Starting from a well-defined local Lagrangian, we analyze the renormalization group equations in terms of the two different arbitrary scales associated with the regularization procedure and with the physical renormalization of the bare parameters, respectively. We apply our formalism to the minimal subtraction scheme using dimensional regularization. We first argue that the relevant regularization scale in this case should be dimensionless. By relating bare and renormalized parameters to physical observables, we calculate the coefficients of the renormalization group equation up to two-loop order in the [Formula: see text] theory. We show that the usual assumption, considering the bare parameters to be independent of the regularization scale, is not a direct consequence of any physical argument. The coefficients that we find in our two-loop calculation are identical to the standard practice. We finally comment on the decoupling properties of the renormalized coupling constant.


2018 ◽  
Vol 47 ◽  
pp. 1860095
Author(s):  
V. E. Rochev

The solution of the equation for the pion propagator in the leading order of the [Formula: see text] – expansion for a vector-matrix model with interaction [Formula: see text] in four dimensions shows a change of the asymptotic behavior in the deep Euclidean region in a vicinity of a certain critical value of the coupling constant.


1990 ◽  
Vol 05 (23) ◽  
pp. 1833-1839 ◽  
Author(s):  
WEI CHEN ◽  
G. W. SEMENOFF ◽  
YONG-SHI WU

The topological Chern-Simons gauge theory is studied in the framework of perturbation theory. Both dimensional and F2 regularizations are used. We demonstrate the vanishing of the beta function up to three loops, the absence of diffeomorphism anomaly in the calculation of two- and three-point functions, and the validity of a topological Ward identity by finite renormalization of the coupling constant. The regularization dependence of the finite renormalization and an ambiguity in the dimensional regularization are also discussed.


2012 ◽  
Vol 10 (02) ◽  
pp. 1250081 ◽  
Author(s):  
SUSAMA AGARWALA

The β function for a scalar field theory describes the dependence of the coupling constant on the renormalization mass scale. This dependence is affected by the choice of regularization scheme. I explicitly relate the β functions of momentum cut-off regularization and dimensional regularization on scalar field theories by a gauge transformation using the Hopf algebras of the Feynman diagrams of the theories.


2004 ◽  
Vol 19 (03) ◽  
pp. 223-238 ◽  
Author(s):  
J. GAMBOA ◽  
J. LÓPEZ-SARRIÓN ◽  
M. LOEWE ◽  
F. MÉNDEZ

The current algebra for gauge theories like QCD at finite temperature and density is studied. We start considering, the massless Thirring model at finite temperature and density, finding an explicit expression for the current algebra. The central charge only depends on the coupling constant and there are not new effects due to temperature and density. From this calculation, we argue how to compute the central charge for QCD4 and we argue why the central charge in four dimensions could be modified by finite temperature and density.


1989 ◽  
Vol 39 (11) ◽  
pp. 1222-1238 ◽  
Author(s):  
J. Hořejší ◽  
J. Novotný ◽  
O. I. Zavialov

Author(s):  
Subhash Mahapatra

AbstractRecently, a novel four-dimensional Gauss–Bonnet theory has been suggested as a limiting case of the original D-dimensional theory with singular Gauss–Bonnet coupling constant $$\alpha \rightarrow \alpha /(D-4)$$ α → α / ( D - 4 ) . The theory is proposed at the level of field equations. Here we analyse this theory at the level of action. We find that the on-shell action and surface terms split into parts, one of which does not scale like $$(D-4)$$ ( D - 4 ) . The limiting $$D\rightarrow 4$$ D → 4 procedure, therefore, gives unphysical divergences in the on-shell action and surface terms in four dimensions. We further highlight various issues related to the computation of counterterms in this theory.


2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Gopal Yadav ◽  
Vikas Yadav ◽  
Aalok Misra

Abstract A (semiclassical) holographic computation of the deconfinement temperature at intermediate coupling from (a top-down) ℳ-theory dual of thermal QCD-like theories, has been missing in the literature. In the process of filling this gap, we demonstrate a novel UV-IR connection, (conjecture and provide evidence for) a non-renormalization beyond one loop of ℳ-chiral perturbation theory [1]-compatible deconfinement Temperature, and show equivalence with an Entanglement (as well as Wald) entropy [2] computation, up to terms Quartic in curvature (R). We demonstrate a Flavor-Memory (FM) effect in the ℳ-theory uplifts of the gravity duals, wherein the no-braner ℳ-theory uplift retains the “memory” of the flavor D7-branes of the parent type IIB dual in the sense that a specific combination of the aforementioned quartic corrections to the metric components precisely along the compact part (given by S3 as an S1-fibration over the vanishing two-cycle S2) of the non-compact four-cycle “wrapped” by the flavor D7-branes, is what determines, e.g., the Einstein-Hilbert action at O(R4). The aforementioned linear combination of 𝒪(R4) corrections to the ℳ-theory uplift [3, 4] metric, upon matching the holographic result from ℳχPT [1] with the phenomenological value of the coupling constant of one of the SU(3) NLO χPT Lagrangian of [5], is required to have a definite sign. Interestingly, in the decompactification (or “MKK → 0”) limit of the spatial circle in [1] to recover a QCD-like theory in four dimensions after integrating out the compact directions, we not only derive this, but in fact obtain the values of the relevant 𝒪(R4) metric corrections. Further, equivalence with Wald entropy for the black hole in the high-temperature ℳ-theory dual at 𝒪(R4) imposes a linear constraint on a similar linear combination of the abovementioned metric corrections. Remarkably, when evaluating the deconfinement temperature from an entanglement entropy computation in the thermal gravity dual, due to a delicate cancellation between the contributions arising from the metric corrections at 𝒪(R4) in the ℳ theory uplift along the S1-fiber and an S2 (which too involves a similar S1-fibration) resulting in a non-zero contribution only along the vanishing S2 surviving, one sees that there are consequently no corrections to Tc at quartic order in the curvature supporting the conjecture made on the basis of a semiclassical computation.


Author(s):  
Jean Zinn-Justin

In preceding chapters, while deriving the scaling behaviour of correlation functions, we have always kept only the leading term in the critical region. We examine now the different corrections to the leading behaviour. For instance, when we have solved the renormalizaton group (RG) equations, so far, we have neglected the small deviation of the effective coupling constant from its fixed-point value. Moreover, to establish RG equations, we have neglected corrections subleading by powers of the cut-off, and effects of other couplings of higher canonical dimensions. Subleading terms related to the value of the effective coupling constant which give the leading corrections, at least near four dimensions, can easily be derived from the solutions of the renormalization group (RG) equations and are discussed first. The situations below and at four dimensions (the upper-critical dimension) have to be examined separately. The second type of corrections involves additional considerations and is examined in the second part of the chapter. The last section is devoted to one physics application, provided by systems with strong dipolar forces, which have 3 as upper-critical dimension.


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