Quark anti-quark entropic force and diffusion constant in a Yang-Mills like theory

The entropic force experienced by a moving quarkonia in a plasma, is computed in a hyperscaling violation background by holography approach. In that case, the axis of the moving quarkonia has an arbitrary angle with wind. We use the results for HSV parameters which obtained in our paper [1] as appropriate values satisfying condition $ImV_{Q\bar{Q}}< 0$. We will show that, in this background the entropic force of the meson shows a decreasing behaviour corresponds to increasing dissociation length. Results of this paper are in agreement with our mentioned work. In addition we will find diffusion constant in an exact case and by an exact approach [2] which satisfies the mentioned condition in there.Comment: 13 pages, 2 figures. arXiv admin note: text overlap with arXiv:1706.0402

Strong Gravitational Lensing in a Charged Squashed Kaluza- Klein G\"{o}del Black hole

In this paper we investigate the strong gravitational lansing in a charged squashed Kaluza-Klein G\"{o}del black hole. The deflection angle is considered by the logarithmic term proposed by Bozza et al. Then we study the variation of deflection angle and its parameters $\bar{a}$ and $\bar{b}$ . We suppose that the supermassive black hole in the galaxy center can be considered by a charged squashed Kaluza-Klein black hole in a G\"{o}del background and by relation between lensing parameters and observables, we estimate the observables for different values of charge, extra dimension and G\"{o}del parameters.Comment: arXiv admin note: substantial text overlap with arXiv:1205.080

Thermodynamics of a charged hairy black hole in (2+1) dimensions

In this paper we study thermodynamics, statistics and spectroscopic aspects of a charged black hole with a scalar hair coupled to the gravity in (2+1) dimensions. We obtained effects of the black hole charge and scalar field on the thermodynamical and statistical quantities. We find that scalar charge may increase entropy, temperature and probability, while may decrease black hole mass, free and internal energy. Also electric charge increases probability and decreases temperature and internal energy. Also we investigate stability of the system and find that the thermodynamical stability exists.Comment: 18 pages, 12 figures. References adde

The stress energy tensor of neutral blackfold and dual theory

In this paper we consider charged and neutral blackfold and extract the Brown-York stress energy tensor. Also, we show that the neutral blackfold spacetime is Ricci- flat and the other spacetime is not. This Ricci-flat condition gives us opportunity to calculate the AAdS spacetime. In order to have dual theory one can consider the AAdS in Fefferman- Graham coordinates. This frame gives correct form of stress tensor in the boundary. The corresponding tensor with using this frame will be traceless and conserved. Such stress tensor is same as perfect fluid and it proves the dual renormalized theory exists for the neutral blackfold .Comment: 12 page

The thermal properties of blackfold and calculation of stress energy tensor

In this paper, we determine thermodynamical quantities for one kind of higher dimensional black holes. We take two charged and neutral blackfold which are higher dimension. We investigate the thermodynamical properties of such black hole at near horizon. By expanding those metrics around horizon, considering periodicity condition of imaginary time and applying some thermodynamical constraints, we extract stress energy tensor of blackfolds. We compare the thermodynamical properties of charged and neutral blackfold. We see here that the stress energy tensor of charged blackfold has brane-tension component in addition to thermal properties. Then by knowing that the spacetime of neutral blackfold is Ricci-flat and there is a nice relation between Ricci-flat and AdS spacetimes we determine the AdS form of Ricci-flat. Also we calculate the corresponding temperature which is satisfied by our previous calculation. Finally, we check the phase transition of blackfolds and show that there is not any critical point for them. So, the thermodynamical stability of both blackfolds will be proven, this result agree with literature.Comment: 11 page

Phase Transition of charged Rotational Black Hole and Quintessence

In this paper, we calculate thermodynamical quantity of Kerr-Newman-AdS black hole solution in quintessence matter. Then, we show that how the rotation and cosmological parameters effect to the thermodynamics properties of black hole. Also, we investigate both types of phase transition for different values of $\omega$ parameter in extended phase space. We notice that type one of phase transition occurs for $P<0.42$ and $a<0.5$. And also we see that the phase transition point shifts to higher entropy when pressure $P$, rotation parameter $a$ and $\alpha$ increase. Also, we find that by changing parameter $\omega$ from -1 to $-\frac{1}{3}$, the critical point shifts to higher entropy. Then we study type two of phase transition and show critical points increase by increasing parameter $\alpha$. Also, we show that the critical point shifts to higher entropy when $\alpha$, $\omega$ and rotation parameter $a$ decrease. Finally, we find that by decreasing pressure the first critical point shifts to lower entropy and second critical point shifts to higher entropy

Screening Length of Rotating Heavy Meson from AdS/CFT

In this paper we consider a quark-antiquark ($q\bar{q}$) pair which can be interpreted as a meson in ${\mathcal{N}}$=4 SYM thermal plasma. We assume that the string moves at speed $v$ and rotates around its center of mass simultaneously. By using the AdS/CFT correspondence, we obtain the momentum densities of the rotating string and determine its motion for small angular velocities. Then in general case, we calculate the screening length of $q\bar{q}$ pair numerically and show that its velocity dependance is in consistent with the well known formula $L_s T\sim (1-v^{2})^{1/4}$ in the literature.Comment: 14 pages, 2 figure. Discussion about screening length added. Submitted to EPJ

The phase transition and holographic in modified Horava -Lifshitz black hole

In this paper, we take cosmological constant as a thermodynamical pressure and it's conjugate quantity as a thermodynamical volume. This expression help us to investigate the phase transition and holographic heat engine. So, in order to have Van der Waals fluid behaviour in Horava -Lifshitz (HL) black hole, we modified the solution of such black hole with some cosmology ansatz. Also from holographic heat engine, we obtain Carnot efficiency for the HL black hole. The phase transition of the system lead us to investigate the stability condition for the corresponding black hole. In that case, we show that the stability exist only in special region of black hole.Comment: 18 pages and 12 figures. arXiv admin note: text overlap with arXiv:1205.0146 by other author

The Thermodynamic Efficiency in Static and Dynamic Black Holes

We note that, in extended phase space the cosmological constant is a thermodynamic variable. In this paper, this cosmological constant lead us to consider a black hole as a heat engine. So, here we take advantage from holographic heat engine and study two kind of different black holes. We first investigate a static black hole (Dyonic BH) and consider the necessary condition to have high efficiency. Also we continue our investigation for dynamic black hole (rotating charged black hole) and study the effect of rotating parameter on the thermodynamic efficiency of holographic heat engine. We show that the rotating parameter has a more effective role than electric charge in thermodynamic efficiency

The effect of Quintessence on the low and high temperature behavior of entanglement entropy for boundary field theory dual to AdS black holes

The effect of dark energy on the low and high temperature of strip region of the boundary field theory dual to AdS black holes was studied. In this framework, we investigate this behavior for different types of equation state and different regimes of normalization factor (a). We will see that the change of entanglement entropy is growing up with increasing a and |\omega|.Comment: 13 pages, 1 figure