386 research outputs found
Free Energies and Probe Actions for Near-horizon D-branes and D1 + D5 System
By working with the free energy for the type II supergravity near-horizon
solution of N coincident non-extremal Dp-branes we study the transitions among
the non-conformal Dp-brane system, the perturbative super Yang-Mills theory and
a certain system associated with M theory. We derive a relation between this
free energy and the action of a Dp-brane probe in the N Dp-brane background.
Constructing the free energy for the five dimensional black hole labeled by the
D1-brane and D5-brane charges we find the similar relation between it and the
action of a D1 or D5 brane probe in the D1 + D5 brane background. These
relations are explained by the massive open strings stretched between the
relevant D-branesComment: 14 pages, LaTeX2e, no figure
ΠΠ°Π³Π½ΠΈΡΠΎΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΈΠΉ Π΄Π²ΠΈΠ³Π°ΡΠ΅Π»Ρ Π΄Π»Ρ ΠΏΡΠΈΠ²ΠΎΠ΄Π° ΡΡΠ»Π΅Π²ΠΎΠΉ ΠΊΠΎΠ»ΠΎΠ½ΠΊΠΈ Π°Π²ΡΠΎΡΡΠ°Π½ΡΠΏΠΎΡΡΠ½ΠΎΠ³ΠΎ ΡΡΠ΅Π΄ΡΡΠ²Π°
ΠΠ°ΡΡΠ½Π°Ρ ΠΊΠ²Π°Π»ΠΈΡΠΈΠΊΠ°ΡΠΈΠΎΠ½Π½Π°Ρ ΡΠ°Π±ΠΎΡΠ° ΠΏΠΎΡΠ΅ΡΠ΅Π½Π° ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΡΠ»ΡΡΠ°ΡΠΈΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΌΠΎΠΌΠ΅Π½ΡΠ° Π² ΠΌΠ°Π³Π½ΠΈΡΠΎΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΎΠΌ Π΄Π²ΠΈΠ³Π°ΡΠ΅Π»Π΅ ΡΡΠ»Π΅Π²ΠΎΠΉ ΠΊΠΎΠ»ΠΎΠ½ΠΊΠΈ Π°Π²ΡΠΎΡΡΠ°Π½ΡΠΏΠΎΡΡΠ½ΠΎΠ³ΠΎ ΡΡΠ΅Π΄ΡΡΠ²Π°. Π ΠΏΠ΅ΡΠ²ΠΎΠΉ Π³Π»Π°Π²Π΅ Π²ΡΠΏΠΎΠ»Π½Π΅Π½ ΠΎΠ±Π·ΠΎΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΉ Π½Π° ΡΠ΅ΠΌΡ ΠΌΠ°Π³Π½ΠΈΡΠΎΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΌΠ°ΡΠΈΠ½ Ρ ΡΠ°Π·Π»ΠΈΡΠ½ΠΎΠΉ ΠΊΠΎΠΌΠΏΠΎΠ½ΠΎΠ²ΠΊΠΎΠΉ ΠΌΠ°Π³Π½ΠΈΡΠΎΠ² Π½Π° ΡΠΎΡΠΎΡΠ΅ ΠΈ ΠΎΡΡΡΠ΅ΡΡΠ²Π»Π΅Π½Π° ΠΏΠΎΡΡΠ°Π½ΠΎΠ²ΠΊΠ° Π·Π°Π΄Π°ΡΠΈ Π½Π°ΡΡΠ½ΠΎΠΉ ΠΊΠ²Π°Π»ΠΈΡΠΈΠΊΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΡΠ°Π±ΠΎΡΡ. ΠΠΎ Π²ΡΠΎΡΠΎΠΉ Π³Π»Π°Π²Π΅ ΡΠ°ΡΡΠΌΠΎΡΡΠ΅Π½Ρ Π²ΠΎΠΏΡΠΎΡΡ ΠΈΠΌΠΈΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΌΠ°Π³Π½ΠΈΡΠΎΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΌΠ°ΡΠΈΠ½Ρ Π² ΠΊΠΎΠ½Π΅ΡΠ½ΠΎ-ΡΠ»Π΅ΠΌΠ΅Π½ΡΠ½ΠΎΠΉ ΠΊΠΎΠΌΠΏΡΡΡΠ΅ΡΠ½ΠΎΠΉ ΡΡΠ΅Π΄Π΅. ΠΡΠΏΠΎΠ»Π½Π΅Π½ΠΎ ΠΏΠ»Π°Π½ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°, ΠΏΠΎΠ»ΡΡΠ΅Π½Π° Π²Π·Π°ΠΈΠΌΠΎΡΠ²ΡΠ·Ρ ΠΌΠ΅ΠΆΠ΄Ρ ΠΊΠΎΠ»ΠΈΡΠ΅ΡΡΠ²ΠΎΠΌ ΠΏΠ°Π·ΠΎΠ² ΡΠΎΡΠΎΡΠ°, Π·ΡΠ±ΡΠ°ΠΌΠΈ ΡΡΠ°ΡΠΎΡΠ°, ΠΊΠΎΡΡΡΠΈΡΠΈΠ²Π½ΠΎΠΉ ΡΠΈΠ»Ρ ΠΌΠ°Π³Π½ΠΈΡΠΎΠ² Ρ ΠΏΠΎΠ·ΠΈΡΠΈΠΈ Π·Π½Π°ΡΠ΅Π½ΠΈΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΌΠΎΠΌΠ΅Π½ΡΠ°. Π ΡΡΠ΅ΡΡΠ΅ΠΉ Π³Π»Π°Π²Π΅ Π²ΡΠΏΠΎΠ»Π½Π΅Π½ ΡΠ°ΡΡΠ΅Ρ ΡΠ²ΡΠ·Π°Π½Π½ΠΎΠΉ ΠΌΠΎΠ΄Π΅Π»ΠΈ ΠΌΠ°Π³Π½ΠΈΡΠΎΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΈΠΉ Π΄Π²ΠΈΠ³Π°ΡΠ΅Π»Ρ-ΠΈΠ½Π²Π΅ΡΡΠΎΡ Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΡ-ΡΠΈΡΡΠ΅ΠΌΠ° ΡΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡ.Scientific qualification work is visited to a research of pulsations of the electromagnetic torque in the magnetoelectric motor of a steering column of the vehicle. In chapter 1 the review of researches on magnetoelectric machine with various configuration of magnets on a rotor is executed and problem definition of scientific qualification work is carried out. In chapter 2 questions of a simulation modeling of the magnetoelectric machine in the terminating and element computer environment are considered. Scheduling of an experiment is executed, the interrelation between quantity of poles of a rotor, tooths of a stator, a coercive force of magnets from a position of values of the electromagnetic torque is received. In a chapter 3 calculation of the bound model the magnetoelectric motor
Automation of the solution of the reverse problems of economic analysis
In this article, we consider the solution of inverse problems of economic analysis by the method of coefficients of relative importance and automation of the solution. The result of the research is the development and implementation of automation of solving the inverse problems of economic analysis, for making decisions in economic problems
Infinite spin limit of semiclassical string states
Motivated by recent works of Hofman and Maldacena and Dorey we consider a
special infinite spin limit of semiclassical spinning string states in AdS5 x
S5. We discuss examples of known folded and circular 2-spin string solutions
and demonstrate explicitly that the 1-loop superstring correction to the
classical expression for the energy vanishes in the limit when one of the spins
is much larger that the other. We also give a general discussion of this limit
at the level of integral equations describing finite gap solutions of the
string sigma model and argue that the corresponding asymptotic form of the
string and gauge Bethe equations is the same.Comment: 38 pages, 3 figures; v2: comments on derivation of bound states of
magnons from discrete Bethe equations added in section 4 and appendix C,
references added, Imperial-TP-AT-6-4, HUTP-06/A002
Three Spin Spiky Strings in beta-deformed Background
We study rigidly rotating strings in -deformed
background with one spin along AdS and two angular momenta along . We
find the spiky string solutions and present the dispersion relation among
various charges in this background. We further generalize the result to the
case of four angular momenta along .Comment: 12 pages, minor corrections, added references, to appear in JHE
Physical simulation of wind pressure on building models at various arrangement and airflow conditions
The results of modeling and distribution of the pressure coefficient on the faces of the faces of the model of a high-rise building with a relative height of H/a = 3 and 6 are obtained under the influence of vortex flows created by an obstacle with similar geometric parameters with its lateral displacement from the longitudinal axis of the channel. The accepted range of transverse displacements is L2/a = 0.5; 1; 1.5; 2. In the range of studies, the airflow angle of 0 degrees was adopted with the maximum Reynolds number (Re) = 4.25Β΄104. The distances between the models in the wake correspond to the calibers L1/a = 1.5; 3 and 6. A series of experiments was carried out on the basis of the theory of modeling. The experiments are based on the modeling of the model buildings under study on the basis of the similarity theory. Systematic data are obtained on the distribution of the pressure coefficients Cp on the faces of the model, depending on its location in the track of the upstream model with a change in the distance between them in the transverse direction relative to the direction of the air flow
Spiky strings and single trace operators in gauge theories
We consider single trace operators of the form O_{m_1 ... m_n} = tr D_+^{m_1}
F ... D_+^{m_n} F which are common to all gauge theories. We argue that, when
all m_i are equal and large, they have a dual description as strings with
cusps, or spikes, one for each field F. In the case of N=4 SYM, we compute the
energy as a function of angular momentum by finding the corresponding solutions
in AdS_5 and compare with a 1-loop calculation of the anomalous dimension. As
in the case of two spikes (twist two operators), there is agreement in the
functional form but not in the coupling constant dependence. After that, we
analyze the system in more detail and find an effective classical mechanics
describing the motion of the spikes. In the appropriate limit, it is the same
(up to the coupling constant dependence) as the coherent state description of
linear combinations of the operators O_{m_1 ... m_n} such that all m_i are
equal on average. This agreement provides a map between the operators in the
boundary and the position of the spikes in the bulk. We further suggest that
moving the spikes in other directions should describe operators with
derivatives other than D_+ indicating that these ideas are quite generic and
should help in unraveling the string description of the large-N limit of gauge
theories.Comment: 23 pages, 5 figures. v2: References and comments adde
Folded Three-Spin String Solutions in AdS_5 x S^5
We construct a spinning closed string solution in AdS_5 x S^5 which is folded
in the radial direction and has two equal spins in AdS_5 and a spin in S^5. The
energy expression of the three-spin solution specified by the folding and
winding numbers for the small S^5 spin shows a logarithmic behavior and a
one-third power behavior of the large total AdS_5 spin, in the long string and
in the short string located near the boundary of AdS_5 respectively. It
exhibits the non-regular expansion in the 't Hooft coupling constant, while it
takes the regular one when the S^5 spin becomes large.Comment: 14 pages, LaTeX, no figures, a reference adde
ΠΠ΅ΠΎΠ»ΠΎΠ³ΠΈΡ ΠΈ Π³Π΅ΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠ° ΠΠ°ΡΡΠ°ΠΊΠΏΠ°ΠΉ-Π£Π»ΡΡΠ°ΡΡΠΊΠΎΠΉ Π·ΠΎΠ½Ρ Π³Π΅ΠΎΡΡΡΡΡ ΠΈ Π΅Π΅ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Ρ Π½Π° ΠΏΠΎΠ»Π΅Π·Π½ΡΠ΅ ΠΈΡΠΊΠΎΠΏΠ°Π΅ΠΌΡΠ΅
Generalized pulsating strings
In this paper we consider new solutions for pulsating strings. For this
purpose we use tha idea of the generalized ansatz for folded and circular
strings in hep-th/0311004. We find the solutions to the resulting
Neumann-Rosochatius integrable system and the corrections to the energy. To do
that we use the approach developed by Minahan in hep-th/0209047 and find that
the corrections are quite different from those obtained in that paper and
hep-th/0310188. We conclude with comments on our solutions and obtained
corrections to the energy, expanded to the leading order in lambda.Comment: v.2 references added, citations corrected, 18 page
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