27,531 research outputs found
Why Do Firms Evade Taxes? The Role of Information Sharing and Financial Sector Outreach
Informality is a wide-spread phenomenon across the globe. We show that firms in countries with better information sharing systems and greater financial sector outreach evade taxes to a lesser degree, an effect that is stronger for smaller firms, firms in smaller cities and towns, and firms in industries relying more on external financing, with higher liquidity needs and with greater growth potential. However, it is variation in firm size that dominates firm variation in location and industry variation in explaining cross-firm and cross-country variation in tax evasion. This effect is robust to controlling for an array of other measures of the financial and institutional environment firms face. The effect is also robust to controlling for fixed firm effects in a smaller panel dataset of Central and Eastern European countries many of which introduced credit registries or upgraded them in the early 2000s.Formal and informal sector;tax evasion;financial sector development
Unique phase diagram with narrow superconducting dome in EuFe(AsP) due to Eu local magnetic moments
The interplay between superconductivity and Eu magnetic moments in
EuFe(AsP) is studied by electrical resistivity measurements
under hydrostatic pressure on and single crystals. We can map
hydrostatic pressure to chemical pressure and show, that superconductivity
is confined to a very narrow range in the phase diagram,
beyond which ferromagnetic (FM) Eu ordering suppresses superconductivity. The
change from antiferro- to FM Eu ordering at the latter concentration coincides
with a Lifshitz transition and the complete depression of iron magnetic order.Comment: 4 page
Superstatistical modelling of protein diffusion dynamics in bacteria
A recent experiment [Sadoon AA, Wang Y. 2018 Phys. Rev. E 98, 042411] has
revealed that nucleoid associated proteins (i.e., DNA-binding proteins) exhibit
highly heterogeneous diffusion processes in bacteria where not only the
diffusion constant but also the anomalous diffusion exponent fluctuates for the
various proteins. The distribution of displacements of such proteins is
observed to take a q-Gaussian form, which decays as a power law. Here, a
statistical model is developed for the diffusive motion of the proteins within
the bacterium, based on a superstatistics with two variables. This model
hierarchically takes into account the joint fluctuations of both the anomalous
diffusion exponents and the diffusion constants. A fractional Brownian motion
is discussed as a possible local model. Good agreement with the experimental
data is obtained.Comment: 48 pages, 4 figures. The discussion has been developed further and
some additional references were added. Published versio
Radio and X-ray nebulae associated with PSR J1509-5850
We have discovered a long radio trail at 843 MHz which is apparently
associated with middle age pulsar PSR J1509-5850. The radio trail has a length
of ~7 arcmin. In X-rays, Chandra observations of PSR J1509-5850 reveal an
associated X-ray trail which extends in the same orientation as the radio
trail. Moreover, two clumpy structures are observed along the radio trail. The
larger one is proposed to be the supernova remnant (SNR) candidate MSC
319.9-0.7. Faint X-ray enhancement at the position of the SNR candidate is
found in the Chandra data.Comment: Accepted by A&A, 5 pages, 4 figures, 1 tabl
Mirror Descent and Convex Optimization Problems With Non-Smooth Inequality Constraints
We consider the problem of minimization of a convex function on a simple set
with convex non-smooth inequality constraint and describe first-order methods
to solve such problems in different situations: smooth or non-smooth objective
function; convex or strongly convex objective and constraint; deterministic or
randomized information about the objective and constraint. We hope that it is
convenient for a reader to have all the methods for different settings in one
place. Described methods are based on Mirror Descent algorithm and switching
subgradient scheme. One of our focus is to propose, for the listed different
settings, a Mirror Descent with adaptive stepsizes and adaptive stopping rule.
This means that neither stepsize nor stopping rule require to know the
Lipschitz constant of the objective or constraint. We also construct Mirror
Descent for problems with objective function, which is not Lipschitz
continuous, e.g. is a quadratic function. Besides that, we address the problem
of recovering the solution of the dual problem
Irreversibility on the Level of Single-Electron Tunneling
We present a low-temperature experimental test of the fluctuation theorem for
electron transport through a double quantum dot. The rare entropy-consuming
system trajectories are detected in the form of single charges flowing against
the source-drain bias by using time-resolved charge detection with a quantum
point contact. We find that these trajectories appear with a frequency that
agrees with the theoretical predictions even under strong nonequilibrium
conditions, when the finite bandwidth of the charge detection is taken into
account
Study of ambiguities in scattering amplitudes
Amplitudes for the reaction are reconstructed from
data on the differential cross section , the recoil
polarization , and on the spin rotation parameter . At low energies,
no data on exist, resulting in ambiguities. An approximation using
and waves leads only to a fair description of the data on
and ; in this case, there are two sets of amplitudes. Including waves,
the data on and are well reproduced by the fit but now,
there are several distinct solutions which describe the data with identical
precision. In the range where the spin rotation parameter was measured,
a full and unambiguous reconstruction of the partial wave amplitudes is
possible. The energy-independent amplitudes are compared to the energy
dependent amplitudes which resulted from a coupled channel fit (BnGa2011-02) to
a large data set including both pion and photo-induced reactions. Significant
deviations are observed. Consistency between energy dependent and energy
independent solutions by choosing the energy independent solution which is
closest to the energy dependent solution. In a second step, the {\it known}
energy dependent solution for low (or high) partial waves is imposed and only
the high (or low) partial waves are fitted leading to smaller uncertainties
Remarkable change of tunneling conductance in YBCO films in fields up to 32.4T
We studied the tunneling density of states in YBCO films under strong
currents flowing along node directions. The currents were induced by fields of
up to 32.4T parallel to the film surface and perpendicular to the
planes. We observed a remarkable change in the tunneling conductance at high
fields where the gap-like feature shifts discontinuously from 15meV to a lower
bias of 11meV, becoming more pronounced as the field increases. The effect
takes place in increasing fields around 9T and the transition back to the
initial state occurs around 5T in decreasing fields. We argue that this
transition is driven by surface currents induced by the applied magnetic field.Comment: 4 pages, 7 figure
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