Lattice electrons in constant magnetic field: Bethe like ansatz

We use the functional representation of Heisenberg-Weyl group and obtain equation for the spectrum of the model, which is more complicated than Bethes ones, but can be written explicitly through theta functions.Comment: 8 pages, LATE

Comparative Studies of Cross-border M&A and Greenfield Investments in Response to Changes in Tax Regulation and Administration of Host Economies

We study and compare the impact of tax indicators, described by Paying Taxes scores of Doing Business report, on two modes of FDI in equity capital- greenfield FDI and cross-border mergers and acquisitions (M&As). Then, we apply 25 percent improvement to each tax factor and evaluate this effect on inbound flow of FDI determinants. The study compares four methods-the ordinary least squares, random-effects, fixed-effects, and Hausman-Taylor models- applied to the panel data for one hundred sixty countries for the period from 2009 to 2017. The consummate range of Hausman-Taylor tools when applied to studies of panel datasets with time-varying, time-invariant and endogenous parameters of tax administration reveals the divergence among the factors appealing to M&A and greenfield investors. The study assesses the higher sensitivity of M&A to the factors of economic development, overall business friendliness and location of a potential host economy. The countries at the lower end of GDP per capita performance are more likely to attract foreign direct investments, if the message about the domestic reforms in tax regulations and administration targets greenfield investors

The Effects of Presumptive Methods of Taxation on Revenue Mobilization in the Value

Recent economic studies of presumptive taxation in the ECA region suggest negative effects of these tax modes on tax revenues mobilization. This study uses a three-stage methodology to estimate the effect of presumptive taxation on revenue mobilization for the VAT. First, we develop a new approach to estimate the true VAT potential tax base in an economy that includes presumptive taxation. Next, the paper assesses potential tax collections reflecting true taxable capacity and a tax effort index, suggesting the presence of inefficiencies in the tax system and sizable tax avoidance. Second, we use regression analysis to test for the scale of impact of presumptive taxation on VAT collections. Third, we use vector autoregression analysis (VAR) to analyze the bidirectional effect of VAT actual and potential collection and presumptive taxation modes in short and long-term perspective. For contrasting the variance of impact of presumptive taxation on VAT mobilization we use two different presumptive tax modes, simplified tax and presumptive payments, with different tax structures. We use data for Armenia for the numerical application of the analysis. Our findings reveal that, indeed, Armenia’s simplified tax has a significant distorting and diminishing effect on VAT collections. Meanwhile, presumptive payments have a positive impact on VAT mobilization

Can Tax Regulation and Administration Practices Impact Foreign Direct Investments?

We examine the impacts of the indicators contributing to the effectiveness of tax regulation performances described by the topic of Paying Taxes in Doing Business report on the foreign direct investment inflows. We further focus on the effects the same determinants have on two different modes of FDI: greenfield FDI and cross-border mergers and acquisitions (M&As). This study uses panel data of one hundred fifty-six countries across all regions. The methodology applies random effects econometric tool to conduct a global investigation on the relation between the level of tax regulation and administration performances and the types of FDI, with further more focalized extraction of information applied to seventeen geographic regions. The main findings suggest that while the high degree model does not detect strong significant relations between factors of tax administration and types of FDI; however, a more scrupulous analysis by regions reveals strong correlations between effective tax regulations and levels of foreign direct investment flows to host economies. Additionally, the study suggests that differentiated factors of tax administration and regulation tools should be considered due to the regional affiliation of a potential host economy to drive foreign investments. The results of the study can be used as a guidance for country administrators in assessment of those specific determinants that could lead to improvement of targeted types of FDI in their specific country as part of a given region. Also, the investors may find the results useful for the evaluation of tax regulations and administration performances in potential host countries in terms of targeted investments

Localization-delocalization transition in the quasi-one-dimensional ladder chain with correlated disorder

The generalization of the dimer model on a two-leg ladder is defined and investigated both, analytically and numerically. For the closed system we calculate the Landauer resistance analytically and found the presence of the point of delocalization at the band center which is confirmed by the numerical calculations of the Lyapunov exponent. We calculate also analytically the localization length index and present the numerical investigations of the density of states (DOS). For the open counterpart of this model the distribution of the Wigner delay times is calculated numerically. It is shown how the localization-delocalization transition manifest itself in the behavior of the distribution.Comment: 9 pages, 10 figures, Revte

Composite fermion state of spin-orbit coupled bosons

We consider spinor Bose gas with the isotropic Rashba spin-orbit coupling in 2D. We argue that at low density its groundstate is a composite fermion state with a Chern-Simons gauge field and filling factor one. The chemical potential of such a state scales with the density as \mu \propto n^{3/2}. This is a lower energy per particle than \mu \propto n for the earlier suggested groundstate candidates: a condensate with broken time-reversal symmetry and a spin density wave state.Comment: 15 pages, 7 figures, Revte

Grassmann-Gaussian integrals and generalized star products

In quantum scattering on networks there is a non-linear composition rule for on-shell scattering matrices which serves as a replacement for the multiplicative rule of transfer matrices valid in other physical contexts. In this article, we show how this composition rule is obtained using Berezin integration theory with Grassmann variables.Comment: 14 pages, 2 figures. In memory of Al.B. Zamolodichiko

Perturbation theory in radial quantization approach and the expectation values of exponential fields in sine-Gordon model

A perturbation theory for Massive Thirring Model (MTM) in radial quantization approach is developed. Investigation of the twisted sector in this theory allows us to calculate the vacuum expectation values of exponential fields $exp iaphi (0)$ of the sine-Gordon theory in first order over Massive Thirring Models coupling constant. It appears that the apparent difficulty in radial quantization of massive theories, namely the explicite ''time'' dependence of the Hamiltonian, may be successfully overcome. The result we have obtained agrees with the exact formula conjectured by Lukyanov and Zamolodchikov and coincides with the analogous calculations recently carried out in dual angular quantization approach by one of the authors.Comment: 16 pages, no figures, LaTe