On cruel mistakes in the calculation of multi-loop superstring amplitudes, the ambiguity of the modular integral and the integration over the module space

Widely spread cruel misconceptions and mistakes in the calculation of multi-loop superstring amplitudes are exposed. Correct calculations are given. It is shown that the cardinal mistake in the gauge fixing procedure presents ab ovo in the Verlinde papers. The mistake was reproduced in following proposals including the recent papers. The modular symmetry of the multi-loop superstring amplitudes is clarified, an incorrectness of previous conjectures being shown. It is shown that the Berezin-type integral versus boson and fermion moduli is doubt under non-split transformations mixing fermion integration variables to the boson integration ones. In particular, due to singularities in moduli of the given spin structure, the integral can be finite or divergent dependently on the integration variables employed. Hence, unlike naive expectations, the multi-loop superstring amplitude is ambiguous. Nevertheless, the ambiguity is totally resolved by the requirement to preserve local symmetries of the superstring amplitude. In the Verlinde world-sheet description it includes, among other thing, the requirement that the amplitude is independent of the gravitino field locations. In action the resolution of the ambiguity in the Verlinde scheme is achieved by going to the supercovariant gauge. As it has been argued earlier, the resulted arbitrary-loop amplitudes are finite.Comment: 28 page

Finiteness of multi-loop superstring amplitudes

Superstring amplitudes of an arbitrary genus are calculated through super-Schottky parameters by a summation over the fermion strings. For a calculation of divergent multi-loop fermion string amplitudes a supermodular invariant regularization procedure is used. A cancellation of divergences in the superstring amplitudes is established. Grassmann variables are integrated, the superstring amplitudes are obtained to be explicitly finite and modular invariant.Comment: 16 pages, LaTe

Explicit Calculation of Multiloop Amplitudes in the Superstring Theory

Multiloop superstring amplitudes are calculated in the explicit form by the solution of Ward identities. A naive generalization of Belavin-Knizhnik theorem to the superstring is found to be incorrect since the period matrix turns out to be depended on the spinor structure over the terms proportional to odd moduli. These terms appear because fermions mix bosons under the two-dim. supersymmetry transformations. The closed, oriented superstring turns out to be finite, if it possesses the ten-dimensional supersymmetry, as well as the two-dimentional one. This problem needs a further study.Comment: 13 pages, LATEX, Preprint PNPI-1872, May 199

Remarks on the formation and decay of multidimensional shock waves

In this paper, we present a formula describing the formation and decay of shock wave type solutions in some special cases.Comment: Latex, 7

The calculation of Feynman diagrams in the superstring perturbation theory

The method of the calculation of the multi-loop superstring amplitudes is proposed. The amplitudes are calculated from the equations that are none other than Ward identities. They are derived from the requirement that the discussed amplitudes are independent from a choice of gauge of both the vierbein and the gravitino field. The amplitudes are calculated in the terms of the superfields vacuum correlators on the complex (1|1) supermanifolds. The superconformal Schottky groups appropriate for this aim are built for all the spinor structures. The calculation of the multi- loop boson emission amplitudes in the closed, oriented Ramond-Neveu-Schwarz superstring theory is discussed in details. The main problem arises for those spinor structures that correspond to the Ramond fermion loops. Indeed, in this case the superfield vacuum correlators can not be derived by a simple extension of the boson string results. The method of the calculation of the above correlators is proposed. The discussed amplitudes due to all the even spinor structures is given in the explicit form.Comment: 48 pages, LATE

Calculation of multi-loop superstring amplitudes

Multi-loop interaction amplitudes in the theory of the closed, oriented superstrings are obtained by the integration of local amplitudes which are represented by a sum of the spinning string local amplitudes. The last local amplitudes are given explicitly through super-Schottky group parameters and interaction vertex coordinates on the $(1|1)$ complex supermanifold. The integration is ambiguous under those replacements of the integration variables which admix Grassmann variables to the boson ones. So the calculation is guided by a preservation of local symmetries of the superstring. The obtained amplitudes are free from divergences and consistent with the world-sheet symmetries. The vacuum amplitude and 1-, 2- and 3-point amplitudes of massless states vanish once the integration over certin modular variables and interaction vertex coordinates.Comment: 47 pages, LATE

Using of unitarity equations for the calculation of fermion interaction amplitudes in the superstring theory

The unitarity equations for the boson interaction amplitudes in the superstring theory are used to calculate the interaction amplitudes including the Ramond states, which are 10-fermion and Ramond bosons. The n-loop, 4-point amplitude with two massless Neveu-Schwarz bosons and two massless Ramond states is obtained explicitly. It is shown that, in addition, the unitarity equations require some integral relations for local functions determining the amplitude. For the tree amplitude the validness of the above integral relations is verified.Comment: 18 pp, Late

Manifest calculation and the finiteness of the superstring Feynman diagrams

The multi-loop amplitudes for the closed, oriented superstring are represented by finite dimensional integrals of explicit functions calculated through the super-Schottky group parameters and interaction vertex coordinates on the supermanifold. The integration region is proposed to be consistent with the group of the local symmetries of the amplitude and with the unitarity equations. It is shown that, besides the SL(2) group, super-Schottky group and modular one, the total group of the local symmetries includes an isomorphism between sets of the forming group transformations, the period matrix to be the same. The singular integration configurations are studied. The calculation of the integrals over the above configurations is developed preserving all the local symmetries of the amplitude, the amplitudes being free from divergences. The nullification of the 0-, 1-, 2- and 3-point amplitudes of massless states is verified. Vanishing the amplitudes for a longitudinal gauge boson is argued.Comment: 55 pages, LATE

Calculation and modular properties of multi-loop superstring amplitudes

Multi-loop superstring amplitude are calculated in the convenient gauge where Grassmann moduli are carried by the 2D gravitino field. Generally, instead of the modular symmetry, the amplitudes hold the symmetry under modular transformations added by relevant transformations of the 2D local supersymmetry. If a number of loops is larger than 3, the integration measures are not modular forms. In this case the expression for the amplitude contains an integral over the bound of the fundamental region of the modular group.Comment: This is an author-created, un-copy-edited version of an article accepted for publication in Class. Quantum Grav. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any derived from it. Class. Quantum Grav. 29 (2012); The Version of Record is available on-line at http://stacks.iop.org/0264-9381/29/23500

Weak asymptotics method

We present a new method for constructing solutions to nonlinear evolutionary equations describing the propagation and interaction of nonlinear waves.Comment: 15 pages, 2 figure