350 research outputs found
Parliamentary-presidential or presidential-parliamentary republic as modes of one political model or different concepts of government
This research paper deals with the scientific research of institutional-procedural and behavioral attributes, principles and indicators of typology of mixed-type republics in European countries. The conducted scientific analysis gives grounds to argue that the defining directions in this context are the appeal to the problems of formation and activity of governments and the possibility of dissolving parliaments (ie scientific institutional and procedural differentiation of hybrid republican forms), dualism, legality and responsibility of executive bodies, as well as the index of presidential powers and the peculiarities of the dualism of the executive branch
Subjective factors and psychological characteristics of students’ selfrealization as a reflection of their psychological well-being in the process of university learning
The purpose of this research is to determine psychological conditions and signs of students’ selfrealization in university training. Psychological survey methods were used in this research. Students’ needmotivational features, meaning-setting characteristics, self-attitude properties and purposelife orientations were scrutinized. As a result the connection between the level of students’ selfrealization and positive motivation of learning, as well as integrity and meaning consistency of their Selfconcept is stated. The conclusion is made on necessity to apply individual-oriented forms of teachin
On Classical Equivalence Between Noncritical and Einstein Gravity : The AdS/CFT Perspectives
We find that noncritical gravity, a special class of higher derivative
gravity, is classically equivalent to Einstein gravity at the full nonlinear
level. We obtain the viscosity-to-entropy ratio and the second order transport
coefficients of the dual fluid of noncritical gravity to all orders in the
coupling of higher derivative terms. We also compute the holographic
entanglement entropy in the dual CFT of noncritical gravity. All these results
confirm the nonlinear equivalence between noncritical gravity and Einstein
gravity at the classical level.Comment: 19 pages, no figure
The effect of higher derivative correction on and conductivities in STU model
In this paper we study the ratio of shear viscosity to entropy, electrical
and thermal conductivities for the R-charged black hole in STU model. We
generalize previous works to the case of a black hole with three different
charges. Actually we use diffusion constant to obtain ratio of shear viscosity
to entropy. By applying the thermodynamical stability we recover previous
results. Also we investigate the effect of higher derivative corrections.Comment: revised versio
International trends in the justice digitalization development
The authors substantiate the feasibility of introducing digital technology into the modern system of administration of justice. It is noted that the introduction of digital technologies will reduce the time for disposal of legal proceedings, create an independent, but at the same time transparent judicial system, improve the quality of decisions taken by the court and the level of public confidence in the state, and minimize government spending in this are
Membrane paradigm realized?
Are there any degrees of freedom on the black hole horizon? Using the
`membrane paradigm' we can reproduce coarse-grained physics outside the hole by
assuming a fictitious membrane just outside the horizon. But to solve the
information puzzle we need `real' degrees of freedom at the horizon, which can
modify Hawking's evolution of quantum modes. We argue that recent results on
gravitational microstates imply a set of real degrees of freedom just outside
the horizon; the state of the hole is a linear combination of rapidly
oscillating gravitational solutions with support concentrated just outside the
horizon radius. The collective behavior of these microstate solutions may give
a realization of the membrane paradigm, with the fictitious membrane now
replaced by real, explicit degrees of freedom.Comment: 8 pages, Latex, 3 figures (Essay given second place in Gravity
Research Foundation essay competition 2010
Large-N spacetime reduction and the sign and silver-blaze problems of dense QCD
We study the spacetime-reduced (Eguchi-Kawai) version of large-N QCD with
nonzero chemical potential. We explore a method to suppress the sign
fluctuations of the Dirac determinant in the hadronic phase; the method employs
a re-summation of gauge configurations that are related to each other by center
transformations. We numerically test this method in two dimensions, and find
that it successfully solves the silver-blaze problem. We analyze the system
further, and measure its free energy F, the average phase theta of its Dirac
determinant, and its chiral condensate . We show that F and
are independent of mu in the hadronic phase but that, as chiral
perturbation theory predicts, the quenched chiral condensate drops from its
mu=0 value when mu~(pion mass)/2. Finally, we find that the distribution of
theta qualitatively agrees with further, more recent, predictions from chiral
perturbation theory.Comment: 43 pages, 17 figure
Parity-Violating Hydrodynamics in 2+1 Dimensions
We study relativistic hydrodynamics of normal fluids in two spatial
dimensions. When the microscopic theory breaks parity, extra transport
coefficients appear in the hydrodynamic regime, including the Hall viscosity,
and the anomalous Hall conductivity. In this work we classify all the transport
coefficients in first order hydrodynamics. We then use properties of response
functions and the positivity of entropy production to restrict the possible
coefficients in the constitutive relations. All the parity-breaking transport
coefficients are dissipationless, and some of them are related to the
thermodynamic response to an external magnetic field and to vorticity. In
addition, we give a holographic example of a strongly interacting relativistic
fluid where the parity-violating transport coefficients are computable.Comment: 39+1 page
Brownian motion in AdS/CFT
We study Brownian motion and the associated Langevin equation in AdS/CFT. The
Brownian particle is realized in the bulk spacetime as a probe fundamental
string in an asymptotically AdS black hole background, stretching between the
AdS boundary and the horizon. The modes on the string are excited by the
thermal black hole environment and consequently the string endpoint at the
boundary undergoes an erratic motion, which is identified with an external
quark in the boundary CFT exhibiting Brownian motion. Semiclassically, the
modes on the string are thermally excited due to Hawking radiation, which
translates into the random force appearing in the boundary Langevin equation,
while the friction in the Langevin equation corresponds to the excitation on
the string being absorbed by the black hole. We give a bulk proof of the
fluctuation-dissipation theorem relating the random force and friction. This
work can be regarded as a step toward understanding the quantum microphysics
underlying the fluid-gravity correspondence. We also initiate a study of the
properties of the effective membrane or stretched horizon picture of black
holes using our bulk description of Brownian motion.Comment: 54 pages (38 pages + 5 appendices), 5 figures. v2: references added,
clarifications in 6.2. v3: clarifications, version submitted to JHE
- …