Challenges of D=6 N=(1,1) SYM Theory

Maximally supersymmetric Yang-Mills theories have several remarkable properties, among which are the cancellation of UV divergences, factorization of higher loop corrections and possible integrability. Much attention has been attracted to the N=4 D=4 SYM theory. The N=(1,1) D=6 SYM theory possesses similar properties but is nonrenomalizable and serves as a toy model for supergravity. We consider the on-shell four point scattering amplitude and analyze its perturbative expansion within the spin-helicity and superspace formalism. The integrands of the resulting diagrams coincide with those of the N=4 D=4 SYM and obey the dual conformal invariance. Contrary to 4 dimensions, no IR divergences on mass shell appear. We calculate analytically the leading logarithmic asymptotics in all loops. Their summation leads to a Regge trajectory which is calculated exactly. The leading powers of s are calculated up to six loops. Their summation is performed numerically and leads to a smooth function of s. The leading UV divergences are calculated up to 5 loops. The result suggests the geometrical progression which ends up in a finite expression. This leads us to a radical point of view on nonrenormalizable theories.Comment: 11 pages, 2 figures, Late

Divergences in maximal supersymmetric Yang-Mills theories in diverse dimensions

The main aim of this paper is to study the scattering amplitudes in gauge field theories with maximal supersymmetry in dimensions D=6,8 and 10. We perform a systematic study of the leading ultraviolet divergences using the spinor helicity and on-shell momentum superspace framework. In D=6 the first divergences start at 3 loops and we calculate them up to 5 loops, in D=8,10 the first divergences start at 1 loop and we calculate them up to 4 loops. The leading divergences in a given order are the polynomials of Mandelstam variables. To be on the safe side, we check our analytical calculations by numerical ones applying the alpha-representation and the dedicated routines. Then we derive an analog of the RG equations for the leading pole that allows us to get the recursive relations and construct the generating procedure to obtain the polynomials at any order of (perturbation theory) PT. At last, we make an attempt to sum the PT series and derive the differential equation for the infinite sum. This equation possesses a fixed point which might be stable or unstable depending on the kinematics. Some consequences of these fixed points are discussed.Comment: 43 pages, 13 figures, pdf LaTex, v2 minor changes and references adde

Ways of improvement of methodological approaches to the assessment of the effectiveness of physical protection systems of nuclear facilities in consideration of modern requirements and threats

Methodological approaches to the assessment of the effectiveness of physical protection systems developed by Russian and foreign researchers are reviewed. Some ways of improvement of these approaches are offered. They consider tactics overview, application of two-person rule, aspects of inherent safety of nuclear materials, proposals on the use of test reliability data

Constitutionalization of assistance in foreign countries

Legal profession in Russia has taken a category of assistance from constitutional level on a large scale and in different aspects. Significant improvement in characteristics of legal phenomena is a comparative jurisprudence method, and so, there is no exception to the assistance that has been declared in the species diversity of constitutional norms. In this study, commonality of historical development stage was a basis for separation of focus group from Commonwealth countries of Independent States (CIS) constitution

Nonlinear interfacial waves in a constant-vorticity planar flow over variable depth

Exact Lagrangian in compact form is derived for planar internal waves in a two-fluid system with a relatively small density jump (the Boussinesq limit taking place in real oceanic conditions), in the presence of a background shear current of constant vorticity, and over arbitrary bottom profile. Long-wave asymptotic approximations of higher orders are derived from the exact Hamiltonian functional in a remarkably simple way, for two different parametrizations of the interface shape.Comment: revtex, 4.5 pages, minor corrections, summary added, accepted to JETP Letter

VASOMOTOR FUNCTION OF THE ENDOTHELIUM IN PATIENTS WITH CHRONIC KIDNEY DISEASE AND HYPERTENSION

Investigation of the functional state of the vascular endothelium contributes to the further study of the mechanisms of development and pharmacological correction, particularly in hypertensive patients with chronic kidney disease. Material and Results. The study involved 172 patients with arterial hypertension (AH) in patients with chronic kidney disease. In the study of vascular-motor response to decompression and test with nitroglycerin in 60% of cases occur reduced vasodilatory and in 12.6% constrictor response. Normal character of vasodilation was 27.4%. Endothelium-independent vasodilation in the brachial artery decompression was reduced by 51.1% compared with the control. The growth of endothelium-independent vasoconstriction in the degree III AH was reduced to a lesser degree than the endothelium dependent - by 6.5% and 19.4% (p<0.01), respectively. Conclusion. Thus impaired endothelium-mediated autoregulation of vascular tone in hypertensive patients with chronic kidney disease is an important element in the pathogenesis of high blood pressure as one of major adaptation mechanisms