30 research outputs found
On the Beta Function for Anisotropic Current Interactions in 2D
By making use of current-algebra Ward identities we study renormalization of
general anisotropic current-current interactions in 2D. We obtain a set of
algebraic conditions that ensure the renormalizability of the theory to all
orders. In a certain minimal prescription we compute the beta function to all
orders.Comment: 7 pages, 6 figures. v2: References added and typos corrected; v3:
cancellation of finite parts more accurately state
Generalized sine-Gordon/massive Thirring models and soliton/particle correspondences
We consider a real Lagrangian off-critical submodel describing the soliton
sector of the so-called conformal affine Toda model coupled to
matter fields (CATM). The theory is treated as a constrained system in the
context of Faddeev-Jackiw and the symplectic schemes. We exhibit the parent
Lagrangian nature of the model from which generalizations of the sine-Gordon
(GSG) or the massive Thirring (GMT) models are derivable. The dual description
of the model is further emphasized by providing the relationships between
bilinears of GMT spinors and relevant expressions of the GSG fields. In this
way we exhibit the strong/weak coupling phases and the (generalized)
soliton/particle correspondences of the model. The case is also
outlined.Comment: 22 pages, LaTex, some comments and references added, conclusions
unchanged, to appear in J. Math. Phy
Renormalization and redundancy in 2d quantum field theories
We analyze renormalization group (RG) flows in two-dimensional quantum field
theories in the presence of redundant directions. We use the operator picture
in which redundant operators are total derivatives. Our analysis has three
levels of generality. We introduce a redundancy anomaly equation which is
analyzed together with the RG anomaly equation previously considered by
H.Osborn [8] and D.Friedan and A.Konechny [7]. The Wess-Zumino consistency
conditions between these anomalies yield a number of general relations which
should hold to all orders in perturbation theory. We further use conformal
perturbation theory to study field theories in the vicinity of a fixed point
when some of the symmetries of the fixed point are broken by the perturbation.
We relate various anomaly coefficients to OPE coefficients at the fixed point
and analyze which operators become redundant and how they participate in the RG
flow. Finally, we illustrate our findings by three explicit models constructed
as current-current perturbations of SU(2)_k WZW model. At each generality level
we discuss the geometric picture behind redundancy and how one can reduce the
number of couplings by taking a quotient with respect to the redundant
directions. We point to the special role of polar representations for the
redundancy groups.Comment: 59 pages, 5 pdf figures; V3: version equivalent to the version
published in JHEP (up to an additional footnote
INFLUENCE OF EXTERNAL LIGHTING POLLUTION BY THE CHEMICAL DEICING MATERIALS ON TRAFFIC SAFETY OF THE MOTOR VEHICLES
Introduction. Road transport remains the most dangerous form of transportation in our time. On the roads of our country about 25 thousand people are killed per year, are injured and maimed more than 250 000 people per year. In fact, every third traffic accident happens in the night time. Therefore, the question of the motor vehicles trafficâs safety increasing on winter roads continues to be relevant nowadays. The duration of the winter slipperinessâ period in Russia is 5-6 months. One way to prevent the winter slipperiness is the deicing materialsâ application. While motor vehiclesâ driving on the road, which is covered with anti-icing materials, the pollution of the vehiclesâ external lights by anti-icing agents is happen, and this process significantly reduces the illumination of the road and the visibility of the traffic conditions in the darkness time and it also negatively affects the road safety situation. Materials and methods. The analysis of the literary sources, the scientific works and the publications about the problem of the external lighting of the car pollution by the deicing materials, which influences on the driverâs visibility of the traffic conditions in the dark time is made in the article. In addition, the analysis of normative documents, which regulate the requirements to the condition of the operated motor vehicles in terms of the road safety is presented in this research.Results. The modern theory of the vehicleâs operational properties does not contain the results about the illumination influence of the road headlights on the traffic safety in terms of their pollution with chemical deicing materials in dark time. Therefore, the research is aimed to identify the patterns how the lighting devicesâ pollution of the vehicle by anti-icing agents influences on road illumination and visibility.Discussion and conclusion. The question about the motor vehiclesâ safety and about their operating conditions on the winter roads, which cover with the chemical anti-icing agents is urgent nowadays, because of the information lack about the regularities of the reagentsâ influence on the traffic safety in dark time. For this reason, the systematic scientific research should be conducted to obtain new information of such influence