D-brane anomaly inflow revisited

Axial and gravitational anomaly of field theories, when embedded in string theory, must be accompanied by canceling inflow. We give a self-contained overview for various world-volume theories, and clarify the role of smeared magnetic sources in I-brane/D-brane cases. The proper anomaly descent of the source, as demanded by regularity of RR field strengths H's, turns out to be an essential ingredient. We show how this allows correct inflow to be generated for all such theories, including self-dual cases, and also that the mechanism is now insensitive to the choice between the two related but inequivalent forms of D-brane Chern-Simons couplings. In particular, SO(6)_R axial anomaly of d=4 maximal SYM is canceled by the inflow onto D3-branes via the standard minimal coupling to C_4. We also propose how, for the anomaly cancelation, the four types of Orientifold planes should be coupled to the spacetime curvatures, of which conflicting claims existed previously.Comment: 41 pages, references updated; version to appear in JHE

Fano and Kondo resonance in electronic current through nanodevices

Electronic transport through a quantum dot strongly coupled to electrodes is studied within a model with two conduction channels. It is shown that multiple scattering and interference of transmitted waves through both channels lead to Fano resonance associated with Kondo resonance. Interference effects are also pronouncedly seen in transport through the Aharonov-Bohm ring with the Kondo dot, where the current characteristics continuously evolve with the magnetic flux.Comment: 4 pages, 3 figures,a typing error has been correcte

First-principles derivation of the AdS/CFT Y-systems

We provide a first-principles, perturbative derivation of the AdS5/CFT4 Y-system that has been proposed to solve the spectrum problem of N=4 SYM. The proof relies on the computation of quantum effects in the fusion of some loop operators, namely the transfer matrices. More precisely we show that the leading quantum corrections in the fusion of transfer matrices induce the correct shifts of the spectral parameter in the T-system. As intermediate steps we study UV divergences in line operators up to first order and compute the fusion of line operators up to second order for the pure spinor string in AdS5xS5. We also argue that the derivation can be easily extended to other integrable models, some of which describe string theory on AdS4, AdS3 and AdS2 spacetimes.Comment: 45 pages, 5 figures; v2: minor additions, JHEP versio

The low-energy limit of AdS(3)/CFT2 and its TBA

We investigate low-energy string excitations in AdS3 × S3 × T4. When the worldsheet is decompactified, the theory has gapless modes whose spectrum at low energies is determined by massless relativistic integrable S matrices of the type introduced by Al. B. Zamolodchikov. The S matrices are non-trivial only for excitations with identical worldsheet chirality, indicating that the low-energy theory is a CFT2. We construct a Thermodynamic Bethe Ansatz (TBA) for these excitations and show how the massless modes’ wrapping effects may be incorporated into the AdS3 spectral problem. Using the TBA and its associated Y-system, we determine the central charge of the low-energy CFT2 to be c = 6 from calculating the vacuum energy for antiperiodic fermions — with the vacuum energy being zero for periodic fermions in agreement with a supersymmetric theory — and find the energies of some excited states

Finite-gap equations for strings on AdS_3 x S^3 x T^4 with mixed 3-form flux

We study superstrings on AdS_3 x S^3 x T^4 supported by a combination of Ramond-Ramond and Neveu-Schwarz-Neveu-Schwarz three form fluxes, and construct a set of finite-gap equations that describe the classical string spectrum. Using the recently proposed all-loop S-matrix we write down the all-loop Bethe ansatz equations for the massive sector. In the thermodynamic limit the Bethe ansatz reproduces the finite-gap equations. As part of this derivation we propose expressions for the leading order dressing phases. These phases differ from the well-known Arutyunov-Frolov-Staudacher phase that appears in the pure Ramond-Ramond case. We also consider the one-loop quantization of the algebraic curve and determine the one-loop corrections to the dressing phases. Finally we consider some classical string solutions including finite size giant magnons and circular strings.Comment: 44 pages, 3 figures. v2: references and a discussion about perturbative results adde

Off-shell symmetry algebra of the AdS_4 x CP^3 superstring

By direct calculation in classical theory we derive the central extension of the off-shell symmetry algebra for the string propagating in AdS_4 x CP^3. It turns out to be the same as in the case of the AdS_5 x S^5 string. We also elaborate on the kappa-symmetry gauge and explain, how it can be chosen in a way which does not break bosonic symmetries.Comment: 23 page

Integrability, spin-chains and the AdS3/CFT2 correspondence

Building on arXiv:0912.1723, in this paper we investigate the AdS3/CFT2 correspondence using integrability techniques. We present an all-loop Bethe Ansatz (BA) for strings on AdS_3 x S^3 x S^3 x S^1, with symmetry D(2,1;alpha)^2, valid for all values of alpha. This construction relies on a novel, alpha-dependent generalisation of the Zhukovsky map. We investigate the weakly-coupled limit of this BA and of the all-loop BA for strings on AdS_3 x S^3 x T^4. We construct integrable short-range spin-chains and Hamiltonians that correspond to these weakly-coupled BAs. The spin-chains are alternating and homogenous, respectively. The alternating spin-chain can be regarded as giving some of the first hints about the unknown CFT2 dual to string theory on AdS_3 x S^3 x S^3 x S^1. We show that, in the alpha to 1 limit, the integrable structure of the D(2,1;alpha) model is non-singular and keeps track of not just massive but also massless modes. This provides a way of incorporating massless modes into the integrability machinery of the AdS3/CFT2 correspondence.Comment: LaTeX, 38 pages. v2: Corrected misprints in section 6.

Lodz City Tour: The Changing Nature of the Urban Restructuring of a Post-Socialist Industrial City

This paper describes the restructuring of Poland’s third-largest city, Lodz (Łódź). Once a thriving metropolitan hub of textile and clothing manufacturing, Lodz was confronted with the closure of its numerous factories in the early 1990s with Poland’s transition from a planned to a global market economy. The city suffered an abrupt and dramatic decline followed by a redefinition of its economic, spatial and social structures. The paper focuses on the major economic and spatial phenomena taking place in the city in the three decades after the economic collapse. Using an evolutionary approach, it identifies and discusses the gradual shift of Lodz’s restructuring. We claim that the restructuring initially involved mostly organic and spontaneous initiatives of dynamic local and non-local actors, with minor and circumstantial involvement from the local authorities. However, over time, the restructuring of Lodz has become influenced and driven by nationally and EU-set objectives and targeted urban policies, with urban and infrastructural projects as driving vehicles.Jakub Zasina’s portion of this work was supported by the National Science Centre in Poland (grant agreement no. 2016/23/N/HS4/03390)

Zastosowanie specjalnego sposobu wyznaczania sił sterujących do realizacji samonaprowadzania na cel powietrzny przeciwlotniczego pocisku rakietowego z wykorzystaniem metody proporcjonalnej nawigacji

An analysis of application feasibility of a special method for surface-to-air missile (SAM) control during homing on an airborne target was carried out in this paper. A prior implementation of the method was motion control for a gyroscope axis with three degrees of freedom [1, 2] at the stages of spatial seeking and tracking of a detected target. The positive results obtained during that research led to a conclusion that the proposed control method would be appropriate for the determination of the control forces for missile guidance. This method consists in the application of the phase trajectories of control errors. Switching over of the control forces at suitable phase plane points reduced the control errors to zero and facilitated a proper flight path of the SAM. This paper presents a switching algorithm, equations of the kinematics and dynamics of SAM flight, and a number of examples of numerical simulations of the problem contemplated herein. The simulation results were represented in a graphic format.W pracy przeprowadzono analizę możliwości zastosowania specjalnej metody sterowania przeciwlotniczym pociskiem rakietowym podczas naprowadzania na ruchomy cel powietrzny. Wcześniej w oparciu o tę metodę zrealizowane zostało sterowanie ruchem osi giroskopu o trzech stopniach swobody [1, 2] w czasie przeszukiwania przestrzeni i śledzenia wykrytego celu. Otrzymane wtedy pozytywne wyniki dały podstawę do wyciągnięcia wniosku, że zaproponowane sterowanie będzie możliwe do wyznaczania sił sterujących przy naprowadzaniu pocisku rakietowego. Metoda ta polega na wykorzystaniu trajektorii fazowych uchybów sterowania. Przełączanie sił sterujących w odpowiednich punktach płaszczyzny fazowej powoduje sprowadzanie tych uchybów do zera i realizację odpowiedniego toru lotu pocisku rakietowego. Zaprezentowano algorytm przełączania, równania kinematyki i dynamiki lotu pocisku oraz wiele przykładów symulacji numerycznych. Otrzymane wyniki zostały przedstawione w postaci graficznej