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Sep 22, 2013
09/13

by
R. Myrzakulov; S. Vijayalakshmi; G. N. Nugmanova; M. Lakshmanan

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A non-isospectral (2+1) dimensional integrable spin equation is investigated. It is shown that its geometrical and gauge equivalent counterparts is the (2+1) dimensional nonlinear Schr\"odinger equation introduced by Zakharov and studied recently by Strachan. Using a Hirota bilinearised form, line and curved soliton solutions are obtained. Using certain freedom (arbitrariness) in the solutions of the bilinearised equation, exponentially localized dromion-like solutions for the potential is...

Source: http://arxiv.org/abs/solv-int/9704005v1

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39

Sep 22, 2013
09/13

by
R. Myrzakulov

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Using the differential geometry of curves and surfaces the Lakshmanan equivalent counterpart of the M-XXII equation is found ... .

Source: http://arxiv.org/abs/math-ph/9807033v1

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54

Sep 23, 2013
09/13

by
M. E. Rodrigues; M. J. S. Houndjo; D. Momeni; R. Myrzakulov

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In this letter we obtain an exact solution for cylindrically symmetric modified Gauss Bonnet gravity. This metric is a generalization of the vacuum solution of the Levi-Civita in the general relativity. It describes an isotropic perfect fluid one parameter family of the gravitational configurations which can be interpreted as the exterior metric of a cosmic string. By setting the Gauss-Bonnet coupling parameter to zero, we recover the vacuum solution in the Einstein gravity as well.

Source: http://arxiv.org/abs/1212.4488v2

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4.0

Jun 30, 2018
06/18

by
Md. Wali Hossain; R. Myrzakulov; M. Sami; Emmanuel N. Saridakis

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In this paper, we focus on general features of quintessential inflation which is an effort to unify inflation and dark energy using a single scalar field. We describe a class of models of quintessential inflation which can give rise to the tensor to scalar ratio of perturbations consistent with recent BICEP2 measurements. The scale of inflation in the model is around the GUT scale and there is large parameter space consistent with the recent findings.

Topics: High Energy Physics - Theory, Astrophysics, General Relativity and Quantum Cosmology, Cosmology and...

Source: http://arxiv.org/abs/1404.1445

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49

Sep 17, 2013
09/13

by
L. Martina; Kur. Myrzakul; R. Myrzakulov

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The study of the relation between the Weierstrass inducing formulae for constant mean curvature surfaces and the completely integrable euclidean nonlinear sigma-model suggests a connection among integrable sigma -models in a background and other type of surfaces. We show how a generalization of the Weierstrass representation can be achieved and we establish a connection with the Weingarten surfaces. We suggest also a possible generalization for two-dimensional surfaces immersed in a flat space...

Source: http://arxiv.org/abs/math/0207261v1

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57

Sep 23, 2013
09/13

by
K. K. Yerzhanov; P. Yu. Tsyba; Sh. R. Myrzakul; I. I. Kulnazarov; R. Myrzakulov

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In the present work we analyze the g-essence model for the particular Lagrangian: $L=R+2[\alpha X^n+\epsilon Y-V(\psi,\bar{\psi})]$. The g-essence models were proposed recently as an alternative and as a generalization to the scalar k-essence. We have presented the 3 types solutions of the g-essence model. We reconstructed the corresponding potentials and the dynamics of the scalar and fermionic fields according the evolution of the scale factor. The obtained results shows that the g-essence...

Source: http://arxiv.org/abs/1012.3031v1

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53

Sep 23, 2013
09/13

by
K. K. Yerzhanov; Sh. R. Myrzakul; I. I. Kulnazarov; R. Myrzakulov

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This work deals with $F(T)$ gravity models driven by real scalar fields with usual and phantom dynamics. We illustrate the results with examples of current interest, and we find some analytical solutions for scale factors and scalar fields. The results indicate that torsion-scalar models also admit the accelerated expansion of the universe.

Source: http://arxiv.org/abs/1006.3879v1

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5.0

Jun 30, 2018
06/18

by
M. Khurshudyan; B. Pourhassan; R. Myrzakulov; S. Chattopadhyay

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In this paper, we consider an effective quintessence scalar field with a power-law potential interacting with a $P_{b}=\xi q\rho_{b}$ barotropic fluid as a first model, where $q$ is a deceleration parameter. For the second model we assume viscous polytropic gas interacting with the scalar field. We investigate problem numerically and analyze behavior of different cosmological parameter concerning to components and behavior of Universe. We also compare our results with observational data to fix...

Topic: General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1403.3768

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60

Sep 22, 2013
09/13

by
M. Sharif; S. Rani; R. Myrzakulov

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This paper is devoted to study the energy conditions in F(R,T) gravity for FRW universe with perfect fluid, where $R$ is the Ricci scalar and $T$ is the torsion scalar. We construct the general energy conditions in this theory and reduce them in F(R) as well as F(T) theory of gravity. Further, we assume some viable models and investigate bounds on their constant parameters to satisfy the energy condition inequalities. We also plot some of the cases using present-day values of the cosmological...

Source: http://arxiv.org/abs/1210.2714v1

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37

Sep 22, 2013
09/13

by
D. Momeni; R. Myrzakulov; L. Sebastiani; M. R. Setare

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We present the analytic Lifshitz solutions for a scalar field model non minimally coupled with the abelian gauge field in $N$ dimensions. We also consider the presence of cosmological constant $\Lambda$. The Lifshitz parameter $z$ appearing in the solution plays the role of the Lorentz breaking parameter of the model. We investigate the thermodynamical properties of the solutions in two different cases, namely $\Lambda=0$ and $\Lambda\neq0$. Furthermore, we study the hairy black hole solutions...

Source: http://arxiv.org/abs/1210.7965v2

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Jun 25, 2018
06/18

by
G. Abbas; D. Momeni; M. Aamir Ali; R. Myrzakulov; S. Qaisar

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This paper is devoted to study the possibility of forming anisotropic compact stars in modified Gauss-Bonnet, namely called as $f(G)$ theory of gravity which is one of the strong candidates,responsible for the accelerated expansion of the universe. For this purpose, we have used analytical solution of Krori and Barua metric to the Einstein field equations with anisotropic form of matter and power law model of $f(G)$ gravity. To determine the unknown constants in Krori and Barua metric, we have...

Topics: General Relativity and Quantum Cosmology, Solar and Stellar Astrophysics, Astrophysics

Source: http://arxiv.org/abs/1501.00427

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69

Sep 18, 2013
09/13

by
Mubasher Jamil; Sajid Ali; D. Momeni; R. Myrzakulov

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In this paper, we investigate the generalized Saez-Ballester scalar-tensor theory of gravity via Noether gauge symmetry (NGS) in the background of Bianchi type I cosmological spacetime. We start with the Lagrangian of our model and calculate its gauge symmetries and corresponding invariant quantities. We obtain the potential function for the scalar field in the exponential form. For all the symmetries obtained, we determine the gauge functions corresponding to each gauge symmmetry which include...

Source: http://arxiv.org/abs/1201.0895v3

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116

Jul 20, 2013
07/13

by
V. Dzhunushaliev; K. Myrzakulov; R. Myrzakulov

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The boson star filled with two interacting scalar fields is investigated. The scalar fields can be considered as a gauge condensate formed by SU(3) gauge field quantized in a non-perturbative manner. The corresponding solution is regular everywhere, has a finite energy and can be considered as a quantum SU(3) version of the Bartnik - McKinnon particle-like solution.

Source: http://arxiv.org/abs/gr-qc/0604110v6

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48

Sep 17, 2013
09/13

by
V. Dzhunushaliev; K. Myrzakulov; R. Myrzakulov

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The model of dark matter is presented where the dark matter is a \emph{classical} gauge field. A spherical symmetric solution of Yang-Mills equation is obtained. The asymptotic behavior of the gauge fields and matter density is investigated. It is shown that the distribution of the matter density allows us interpret it as the dark matter. The fitting of a typical rotational curve with the rotational curve created by the spherical solution of SU(3) Yang-Mills equation is made.

Source: http://arxiv.org/abs/0912.4311v3

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7.0

Jun 30, 2018
06/18

by
Sarita Rani; A. Altaibayeva; M. Shahalam; J. K. Singh; R. Myrzakulov

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In this paper, we examine observational constraints on the power law cosmology; essentially dependent on two parameters $H_0$ (Hubble constant) and $q$ (deceleration parameter). We investigate the constraints on these parameters using the latest 28 points of H(z) data and 580 points of Union2.1 compilation data and, compare the results with the results of $\Lambda$CDM. We also forecast constraints using a simulated data set for the future JDEM, supernovae survey. Our studies give better insight...

Topics: Astrophysics, General Relativity and Quantum Cosmology, Cosmology and Nongalactic Astrophysics

Source: http://arxiv.org/abs/1404.6522

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48

Sep 20, 2013
09/13

by
Kazuharu Bamba; Antonio Lopez-Revelles; R. Myrzakulov; S. D. Odintsov; L. Sebastiani

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A generic feature of viable $F(R)$ gravity is investigated: It is demonstrated that during the matter dominated era the large frequency oscillations of the effective dark energy may influence the behavior of higher derivatives of the Hubble parameter with the risk to produce some singular unphysical solutions at high redshift. This behavior is explicitly analyzed for realistic $F(R)$ models, in particular, exponential gravity and a power form model. To stabilize such oscillations, we consider...

Source: http://arxiv.org/abs/1207.1009v2

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44

Sep 19, 2013
09/13

by
V. Dzhunushaliev; V. Folomeev; K. Myrzakulov; R. Myrzakulov

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The model of cosmic string formed from two gravitating and interacting scalar fields is considered. It is shown that the regular solutions exist at special choice of the model's parameters only.

Source: http://arxiv.org/abs/gr-qc/0610111v3

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7.0

Jun 30, 2018
06/18

by
S. K. J. Pacif; K. Myrzakulov; R. Myrzakulov

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We reconstruct the field potentials in case of (non)phantom fields for different models resulting from parametrization of q(t), a(t) or H(t). In addition we carry out similar procedure for tachyonic field. We also discuss specific form of parametrization for reconstruction of scalar field potential.

Topic: General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1702.01028

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10.0

Jun 26, 2018
06/18

by
D. Momeni; R. Myrzakulov; E. Güdekli

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Extended $f(R)$ theories of gravity have been investigated from the symmetry point of view. We briefly has been investigated Noether symmetry of two types of extended $f(R)$ theories: $f(R,T)$ theory, in which curvature is coupled non minimally to the trace of energy momentum tensor $T_{\mu\nu}$ and mimetic $f (R) $ gravity, a theory with a scalar field degree of freedom, but ghost-free and with internal conformal symmetry. In both cases we write point -like Lagrangian for flat...

Topic: General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1502.00977

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4.0

Jun 30, 2018
06/18

by
M. Zhassybayeva; G. Mamyrbekova; G. Nugmanova; R. Myrzakulov

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The Myrzakulov-Lakshmanan-II (ML-II) equation is one of a (2+1)-dimensional generalizations of the Heisenberg ferromagnetic equation. It is integrable and has a non-isospectral Lax representation. In this paper, the Darboux transformation (DT) for the ML-II equation is constructed. Using the DT, the 1-soliton and 2-soliton solutions of the ML-II equation are presented.

Topics: Nonlinear Sciences, Exactly Solvable and Integrable Systems

Source: http://arxiv.org/abs/1404.7733

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8.0

Jun 30, 2018
06/18

by
Z. S. Yersultanova; M. Zhassybayeva; K. Yesmakhanova; G. Nugmanova; R. Myrzakulov

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Integrable Heisenberg ferromagnetic equations are an important subclass of integrable systems. The M-XCIX equation is one of a generalizations of the Heisenberg ferromagnetic equation and are integrable. In this paper, the Darboux transformation of the M-XCIX equation is constructed. Using the DT, a 1-soliton solution of the M-XCIX equation is presented.

Topics: Nonlinear Sciences, Exactly Solvable and Integrable Systems

Source: http://arxiv.org/abs/1404.2270

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4.0

Jun 30, 2018
06/18

by
G. Shaikhova; K. Yesmakhanova; G. Mamyrbekova; R. Myrzakulov

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In this paper, we construct a Darboux transformation (DT) of the (2+1)-dimensional Schr\"odinger-Maxwell-Bloch equation (SMBE) which is integrable by the Inverse Scattering Method. Using this DT, the one-soliton solution and periodic solution are obtained from the "seed" solutions.

Topics: Nonlinear Sciences, Exactly Solvable and Integrable Systems

Source: http://arxiv.org/abs/1402.4669

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45

Sep 17, 2013
09/13

by
T. A. Kozhamkulov; Kuralay Myrzakul; R. Myrzakulov

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We conjecture that many (maybe all) integrable equations and spin systems in 2+1 dimensions can be obtained from the (2+1)-dimensional Gauss-Mainardi-Codazzi and Gauss-Weingarten equations, respectively. We also show that the (2+1)-dimensional Gauss-Mainardi-Codazzi equation which describes the deformation (motion) of surfaces is the exact reduction of the Yang-Mills-Higgs-Bogomolny and Self-Dual Yang-Mills equations. On the basis of this observation, we suggest that the (2+1)-dimensional...

Source: http://arxiv.org/abs/nlin/0207046v1

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47

Sep 18, 2013
09/13

by
L. Martina; Kur. Myrzakul; R. Myrzakulov; G. Soliani

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A few years ago, some of us devised a method to obtain integrable systems in (2+1)-dimensions from the classical non-Abelian pure Chern-Simons action via reduction of the gauge connection in Hermitian symmetric spaces. In this paper we show that the methods developed in studying classical non-Abelian pure Chern-Simons actions, can be naturally implemented by means of a geometrical interpretation of such systems. The Chern-Simons equation of motion turns out to be related to time evolving...

Source: http://arxiv.org/abs/nlin/0006039v1

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7.0

Jun 30, 2018
06/18

by
M. Shahalam; S. D. Pathak; Shiyuan Li; R. Myrzakulov; Anzhong Wang

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In this paper, we apply the dynamical analysis to a coupled phantom field with scaling potential taking particular forms of the coupling (linear and combination of linear), and present phase space analysis. We investigate if there exist late time accelerated scaling attractor that has the ratio of dark energy and dark matter densities of the order one. We observe that the scrutinized couplings cannot alleviate the coincidence problem, however acquire stable late time accelerated solutions. We...

Topic: General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1702.04720

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11

Jun 27, 2018
06/18

by
M. Shahalam; S. D. Pathak; M. M. Verma; M. Yu. Khlopov; R. Myrzakulov

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In this paper, we investigate coupled quintessence with scaling potential assuming specific forms of the coupling as $A$ namely, $\alpha \dot{\rho_m}$, $\beta \dot{\rho_{\phi}}$ and $\sigma (\dot{\rho_m}+\dot{\rho_{\phi}})$, and present phase space analysis for three different interacting models. We focus on the attractor solutions that can give rise to late time acceleration with $\Omega_{DE}/\Omega_{DM}$ of order unity in order to alleviate the coincidence problem.

Topic: General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1503.08712

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8.0

Jun 29, 2018
06/18

by
N. S. Mazhari; D. Momeni; Kairat Myrzakulov; R. Myrzakulov

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We studied entanglement entropy for a time dependent two dimensional holographic superconductor. We showed that the conserved charge of the system plays the role of the critical parameter to have condensation.

Topic: High Energy Physics - Theory

Source: http://arxiv.org/abs/1602.08720

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46

Sep 22, 2013
09/13

by
M. R. Setare; D. Momeni; R. Myrzakulov

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In this short letter we calculate separately the generalized uncertainty principle (GUP) and self gravitational corrections to the Newton's gravitational formula. We show that for a complete description of the GUP and self-gravity effects, both temperature and the entropy must be modified.

Source: http://arxiv.org/abs/1004.2794v2

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4.0

Jun 30, 2018
06/18

by
Md. Wali Hossain; R. Myrzakulov; M. Sami; Emmanuel N. Saridakis

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Quintessential inflation refers to an attempt to unify inflation and late-time cosmic acceleration using a single scalar field. In this letter we consider two different classes of quintessential inflation, one of which is based upon a Lagrangian with non-canonical kinetic term $k^2(\phi)\partial^\mu \phi \partial_\mu \phi$ and a steep exponential potential while the second class uses the concept of steep brane world inflation. We show that in both cases the Lyth bound can be evaded, despite the...

Topics: High Energy Physics - Theory, High Energy Physics - Phenomenology, Astrophysics, General Relativity...

Source: http://arxiv.org/abs/1405.7491

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46

Sep 21, 2013
09/13

by
M. J. S. Houndjo; M. E. Rodrigues; D. Momeni; R. Myrzakulov

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We present cylindrically symmetric solutions for a type of the Gauss-Bonnet gravity, in details. We derive the full system of the field equations and show that there exist seven families of exact solutions for three forms of viable models. By applying the method based on the effective fluid energy momentum tensor components, we evaluate the mass per unit length for the solutions. From dynamical point of the view, by evaluating the null energy condition for these configurations, we show that in...

Source: http://arxiv.org/abs/1301.4642v1

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64

Sep 23, 2013
09/13

by
Mubasher Jamil; D. Momeni; N. S. Serikbayev; R. Myrzakulov

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F-essence is a generalization of the usual Dirac model with the nonstandard kinetic term. In this paper, we introduce a new model of spinor cosmology containing both Ricci scalar and the non minimally coupled spinor fields in its action. We have investigated the cosmology with both isotropy and anisotropy, where the equations of motion of FRW and Bianchi type-I spacetimes have been derived and solved numerically. Finally the quantization of these models through Wheeler-De Witt (WD) wave...

Source: http://arxiv.org/abs/1112.4472v1

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6.0

Jun 30, 2018
06/18

by
S. Chattopadhyay; A. Ashurov; M. Khurshudyan; K. Myrzakulov; A. Pasqua; R. Myrzakulov

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In this paper, we study the main cosmological properties of the classical Friedmann equations in the case of homogeneous and isotropic Friedmann-Robertson-Walker Universe and we also generalized the expression of the Friedmann equation in the case of Loop Quantum Cosmology (LQC). Considering the $M_{35}$-model, we found the solutions of the equations considered for two particular cases, i.e. $Q=0$ (i.e., the de Sitter solution) and $Q>0$. Moreover, we considered and studied two exact...

Topic: General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1403.2815

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45

Sep 22, 2013
09/13

by
O. V. Razina; Y. M. Myrzakulov; N. S. Serikbayev; Sh. R. Myrzakul; G. N. Nugmanova; R. Myrzakulov

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We study the two particular models of g-essence with Yukawa type interactions between a scalar field $\phi$ and a classical Dirac field $\psi$. For the homogeneous, isotropic and flat Friedmann-Robertson-Walker universe filled with the such g-essence, some exact solutions of these models are found. Moreover, we reconstruct the corresponding scalar and fermionic potentials.

Source: http://arxiv.org/abs/1101.0729v2

91
91

Sep 23, 2013
09/13

by
I. Kulnazarov; K. Yerzhanov; O. Razina; Sh. Myrzakul; P. Tsyba; R. Myrzakulov

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We study the g-essence model with Yukawa interactions between a scalar field $\phi$ and a Dirac field $\psi$. For the homogeneous, isotropic and flat Friedmann-Robertson-Walker universe filled with the such g-essence, the exact solution of the model is found. Moreover, we reconstruct the corresponding scalar and fermionic potentials which describe the coupled dynamics of the scalar and fermionic fields. It is shown that some particular g-essence models with Yukawa interactions correspond to the...

Source: http://arxiv.org/abs/1012.4669v2

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6.0

Jun 29, 2018
06/18

by
M. Shahalam; S. K. J. Pacif; R. Myrzakulov

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In this paper we study cosmological dynamics of phantom as well as non-phantom fields with linear potential in presence of Galileon correction $(\partial_\mu\phi \partial^\mu\phi) \Box \phi$. We show that the Big Crunch singularity is delayed compared to the standard case; the delay crucially depends upon the strength of Galileon correction. As for the phantom Galileon, $\rho_{\phi}$ is shown to grow more slowly compared to the standard phantom delaying the approach to singularity. In case,...

Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1602.03176

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43

Sep 22, 2013
09/13

by
R. Myrzakulov

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Gauge equivalence between the two-dimensional continuous classical Heisenberg ferromagnets(CCHF) of spin 1/2 - the M-I equation with single site anisotropy and the Zakharov equation(ZE) is established for the easy axis case. The anisotropic CCHF is shown to be gauge equivalent to the isotropic CCHF.

Source: http://arxiv.org/abs/cond-mat/9805188v1

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5.0

Jun 29, 2018
06/18

by
V. G. Makhankov; R. Myrzakulov; O. K. Pashaev

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An integrable generalization of the continuous classical O$(2,1)$ pseudospin Heisenberg model to the case of the ospu$(1,1/1)$ superalgebra is constructed. The gauge equivalence of the constructed model and the related NLSE is established. We indicate a method of generating classical solutions using the global ospu$(1,1/1)$ supersymmetry. The relationship between solutions of O$(2,1)$ HM and 'superpartners' of NLSE is obtained.

Topics: Exactly Solvable and Integrable Systems, Nonlinear Sciences

Source: http://arxiv.org/abs/1612.09124

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9.0

Jun 28, 2018
06/18

by
D. Momeni; P. H. R. S. Moraes; R. Myrzakulov

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We present a study of the generalized second law of thermodynamics in the scope of the f(R,T) theory of gravity, with R and T representing the Ricci scalar and trace of the energy-momentum tensor, respectively. From the energy-momentum tensor equation for the f(R,T) = R + f(T) case, we calculate the form of the geometric entropy in such a theory. Then, the generalized second law of thermodynamics is quantified and some relations for its obedience in f(R,T) gravity are presented. Those relations...

Topic: General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1512.04755

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123

Sep 18, 2013
09/13

by
Kuralay Myrzakul; R. Myrzakulov

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The L-equivalent counterpart of the M-LXIX equation is found. This L-equivalent equation is the Gauss-Codazzi equation which is integrable by the dressing method. This means that the M-LXIX equation is also integrable in this sense.

Source: http://arxiv.org/abs/math/0110062v1

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6.0

Jun 30, 2018
06/18

by
E. O. Kahya; M. Khurshudyan; B. Pourhassan; R. Myrzakulov; A. Pasqua

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In this paper, we study two different models of dark energy based on Chaplygin gas equation of state. The first model is the variable modified Chaplygin gas while the second one is the extended Chaplygin gas. Both models are considered in the framework of higher order $f(R)$ modified gravity. We also consider the case of time varying gravitational constant $G$ and $\Lambda$ for both models. We investigate some cosmological parameters such as the Hubble, the deceleration and the equation of...

Topic: General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1402.2592

8
8.0

Jun 29, 2018
06/18

by
M. J. S. Houndjo; M. E. Rodrigues; N. S. Mazhari; D. Momeni; R. Myrzakulov

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In literature there is a model of modified gravity in which the matter Lagrangian is coupled to the geometry via trace of the stress-energy momentum tensor $T=T_{\mu}^{\mu}$. This type of modified gravity is called as $f(R,T)$ in which $R$ is Ricci scalar $R=R_{\mu}^{\mu}$. We extend manifestly this model to include the higher derivative term $\Box R$. We derived equation of motion (EOM) for the model by starting from the basic variational principle. Later we investigate FLRW cosmology for our...

Topics: High Energy Physics - Theory, Astrophysics, Cosmology and Nongalactic Astrophysics, General...

Source: http://arxiv.org/abs/1601.00196

5
5.0

Jun 30, 2018
06/18

by
A. I. Ahmadov; C. Aydin; R. Myrzakulov; O. Uzun

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We calculate the contribution of the higher-twist Feynman diagrams to the large-$p_T$ inclusive gluon production cross-section in $\pi p$ collisions in case of the running coupling and frozen coupling approaches within perturbative and holographic QCD. The structure of infrared renormalon singularities of the higher-twist subprocess cross-section is obtained and the resummed higher-twist cross- sections (Borel sum) with the ones obtained in the framework of the frozen coupling approach and...

Topic: High Energy Physics - Phenomenology

Source: http://arxiv.org/abs/1409.4947

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47

Sep 22, 2013
09/13

by
M. R. Setare; D. Momeni; R. Myrzakulov; Muhammad Raza

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In this work we study the analytical properties of a 2+1 dimensional magnetically charged holographic superconductor in $AdS_4$. We obtain the critical chemical potential $\mu_c$ analytically, using the Sturm-Liouville variational approach. Also, the obtained analytic result can be used to back up the numerical computations in the holographic superconductor in the probe limit.

Source: http://arxiv.org/abs/1210.1062v3

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Jun 30, 2018
06/18

by
M. R. Setare; D. Momeni; V. Kamali; R. Myrzakulov

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We propose a generalised de Sitter scale factor for the cosmology of early and late time universe, including single scalar field is called as inflaton. This form of scale factor has a free parameter $q$ is called as nonextensivity parameter. When $q=1$, the scale factor is de Sitter. This scale factor is an intermediate form between power-law and de Sitter. We study cosmology of such families. We show that both kinds of dark components, dark energy and dark matter simultaneously are described...

Topics: Physics, High Energy Physics - Theory, General Physics

Source: http://arxiv.org/abs/1409.3200

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Jun 27, 2018
06/18

by
R. Myrzakulov; L. Sebastiani; S. Vagnozzi

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We investigate inflation within $f(R,\phi)$-theories, where a dynamical scalar field is coupled to gravity. A class of models which can support early-time acceleration with the emerging of an effective cosmological constant at high curvature is studied. The dynamics of the field allow for exit from inflation leading to the correct amount of inflation in agreement with cosmological data. Furthermore, the spectral index and tensor-to-scalar ratio of the models are carefully analyzed. A...

Topic: General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1504.07984

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Sep 17, 2013
09/13

by
R. Myrzakulov; Kur. Myrzakul

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Integrability of the (2+1)-dimensional Gauss-Codazzi-Mainardi equation is considered. It is shown that this equation is the particular cases of the Yang-Mills-Higgs-Bogomolny and self-dual Yang-Mills equations.

Source: http://arxiv.org/abs/math/0108128v1

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Sep 23, 2013
09/13

by
R. Myrzakulov; G. K. Mamyrbekova; G. N. Nugmanova; M. Lakshmanan

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Integrable spin systems possess interesting geometrical and gauge invariance properties and have important applications in applied magnetism and nanophysics. They are also intimately connected to nonlinear Schr\"odinger family of equations. In this paper we identify three different integrable spin systems in (2+1) dimensions by introducing interaction of the spin field with more than one scalar potentials or vector potential or both. We also obtain the associated Lax pairs. We discuss...

Source: http://arxiv.org/abs/1305.0098v1

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Sep 21, 2013
09/13

by
Zh. Kh. Zhunussova; K. R. Yesmakhanova; D. I. Tungushbaeva; G. K. Mamyrbekova; G. N. Nugmanova; R. Myrzakulov

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In this paper, we consider some integrable Heisenberg Ferromagnet Equations with self-consistent potentials. We study their Lax representations. In particular we give their equivalent counterparts which are nonlinear Schr\"odinger type equations. We present the integrable reductions of the Heisenberg Ferromagnet Equations with self-consistent potentials. These integrable Heisenberg Ferromagnet Equations with self-consistent potentials describe nonlinear waves in ferromagnets with some...

Source: http://arxiv.org/abs/1301.1649v2

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Jul 20, 2013
07/13

by
N. S. Serikbaev; Zh. M. Bitibaeva; K. K. Yerzhanov; R. Myrzakulov

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Geometrical flows (GF) play an important role in modern mathematics and physics. In this letter we have considered some integrable isotropic GF -- Ricci flows (RF) and mean curvature flows (MCF) -- which are related with integrable Heisenberg ferromagnets. In 2+1 dimensions, these GF have a singularity at $t=t_{0}$.

Source: http://arxiv.org/abs/0804.0837v1

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Jun 30, 2018
06/18

by
R. Myrzakulov; G. K. Mamyrbekova; G. N. Nugmanova; K. R. Yesmakhanova; M. Lakshmanan

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Motion of curves and surfaces in $\R^3$ lead to nonlinear evolution equations which are often integrable. They are also intimately connected to the dynamics of spin chains in the continuum limit and integrable soliton systems through geometric and gauge symmetric connections/equivalence. Here we point out the fact that a more general situation in which the curves evolve in the presence of additional self consistent vector potentials can lead to interesting generalized spin systems with self...

Topics: Nonlinear Sciences, Differential Geometry, Mathematics, Exactly Solvable and Integrable Systems,...

Source: http://arxiv.org/abs/1404.2088