arXiv subjects

Ardian Nata Atmaja

Publications and source records attributed to Ardian Nata Atmaja.

26 records · Page 2Linked to original sources

arXiv2015

A Method for BPS Equations of Vortices

We develop a new method for obtaining the BPS equations of static vortices motivated by the results of the \textit{On-Shell} method on the standard Maxwell-Higgs model and its Born-Infeld-Higgs model~\cite{Atmaja:2014fha}. Our method relies on the existence of what we shall call an energy function, $Q$, which is a mere function of the (effective) fields. The total energy of BPS vortices, $E_{BPS}$, are simply given by a difference between the boundaries value of $Q$ at $r\to\infty$ and at $r=0$, $E_{BPS}=Q(r\to\infty)-Q(r=0)$. Imposing a condition that these (effective) fields are independent, we may define a BPS Lagrangian, $\mathcal{L}_{BPS}$, derived by taking integral of differential $Q$, $\mathcal{L}_{BPS}=-\int dQ$. Matching the Lagrangian $\mathcal{L}_{BPS}$ with the corresponding effective Lagrangian, we can extract several equations. Solving these equations yields the desired BPS equations and, in some cases, also constraint equations. With our method, the various known BPS equations of vortices are derived in a relatively simple procedure.

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arXiv2015

A Detailed Study of Bogomol'nyi Equations in Two-Dimensional Generalized Maxwell-Higgs Model Using \textit{On-Shell} Method

We use a recent {\it on-shell} Bogomol'nyi method, developed in~\cite{Atmaja:2014fha}, to construct Bogomol'nyi equations of the two-dimensional generalized Maxwell-Higgs model~\cite{Bazeia:2012uc}. The formalism can generate a large class of Bogomol'nyi equations parametrized by a constant $C_0$. The resulting equations are classified into two types, determined by $C_0=0$ and $C_0\neq0$. We identify that the ones obtained by Bazeia {\it et al}~\cite{Bazeia:2012uc} are of the type $C_0=0$. We also reveal, as in the case of ordinary vortex, that this theory does not admit Bogomol'nyi equations in the Bogomol'nyi-Prasad-Sommerfield limit in its spectrum. However, when the vacuum energy is lifted up by adding some constant to the energy density then the existence of such equation is possible. Another possibility whose energy is equal to the vacuum is also discussed in brief. As a future of the \textit{on-shell} method, we find another new Bogomol'nyi equations, for $C_0\neq0$, which are related to a non-trivial function defined as a difference between energy density of potential term of the scalar field and kinetic term of the gauge field.

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arXiv2015

Holographic Screening Length in a Hot Plasma of Two Sphere

We study the screening length of a quark-antiquark pair moving in a hot plasma living in two sphere $S^2$ manifold using AdS/CFT correspondence where the background metric is four dimensional Schwarzschild-AdS black hole. The geodesic solution of the string ends at the boundary is given by a stationary motion in the equatorial plane as such the separation length $L$ of quark-antiquark pair is parallel to the angular velocity $ω$. The screening length and the bound energy are computed numerically using Mathematica. We find that the plots are bounded from below by some functions related to the momentum transfer $P_c$ of the drag force configuration. We compare the result by computing the screening length in the quark-antiquark reference frame where the gravity dual are "Boost-AdS" and Kerr-AdS black holes. Finding relations of the parameters of both black holes, we argue that the relation between mass parameters $M_{Sch}$ of the Schwarzschild-AdS black hole and $M_{Kerr}$ of the Kerr-AdS black hole in high temperature is given by $M_{Kerr}=M_{Sch}(1-a^2l^2)^{3/2}$, where $a$ is the angular momentum parameter.

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arXiv2014

Holographic Brownian Motion and Time Scales in Strongly Coupled Plasmas

We study Brownian motion of a heavy quark in field theory plasma in the AdS/CFT setup and discuss the time scales characterizing the interaction between the Brownian particle and plasma constituents. In particular, the mean-free-path time is related to the connected 4-point function of the random force felt by the Brownian particle. By holographically computing the 4-point function and regularizing the IR divergence appearing in the computation, we write down a general formula for the mean-free-path time, and apply it to the STU black hole which corresponds to plasma charged under three U(1) R-charges. The result indicates that the Brownian particle collides with many plasma constituents simultaneously.

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arXiv2013

Effective Mass of Holographic Brownian Particle in Rotating Plasma

The dynamic of string fluctuation under rotating BTZ black hole is studied using the method of \cite{Son:2009vu}. We compare the result with previous computation in \cite{Atmaja:2012jg}, with a different method, for the case of co-rotating string. The result gives definite answer that the end of string identified as an external quark at the boundary behaves as Brownian particle with mass is given an effective mass $M_{eff}$ equal to the zero temperature mass of external quark $M_0$ times Lorentz factor $γ$ to the power three. We also extend the computation for general case of rotating black hole where the metric is asymptotically $AdS_3$ and the fluctuation is taken only along the co-rotating motion. It shows that the effective mass of the external quark is in general given by $γ^3 M_0$.

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arXiv2013

Holographic Brownian Motion in Two Dimensional Rotating Fluid

The Brownian motion of a heavy quark under a rotating plasma corresponds to BTZ black hole is studied using holographic method from string theory. The position of heavy quark is represented as the end of string at the boundary of BTZ black hole and the corresponding rotating plasma is one dimensional compact space. We requires the angular velocity of the string fluctuation to be equal to the ratio between inner horizon and outer horizon, called terminal angular velocity, which is related to the zero total force condition. We show the displacement square of this solution behaves as a Brownian particle in non-relativistic limit. For relativistic case, we argue that it is more appropriate to compute the leading order of low frequency limit of random-random force correlator. The Brownian motion relates this correlator with physical observables: effective mass of the Brownian particle, friction coefficient, and temperature of the plasma.

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arXiv2013

Application of Harmonic Maps $CP^{(N-1)}$ on SU(N) Bogomolny Equation for BPS Magnetic Monopoles

In this thesis we study dynamic of magnetic monopoles from Lagrangian density in Yang-Mills-Higgs field theory. In particular, we discuss BPS (Bogomolny Prasad Sommerfield) magnetic monopoles, described by SU(N) Bogomolny equations, which has field equations in form of non-linear coupled matrix field equations. One of the methods to simplify SU(N) Bogomolny equations is by using harmonic maps $CP^{(N-1)}$. This method has relation with $Gr(n,N)} σ$-model and can transform SU(N) Bogomolny equation into more simple scalar field equations that depends only on one variable. As an example, we consider the case of SU(2) Bogomolny equation.

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arXiv2011

Anisotropic Drag Force from 4D Kerr-AdS Black Holes

Using AdS/CFT we investigate the effect of angular-momentum-induced anisotropy on the instantaneous drag force of a heavy quark. The dual description is that of a string moving in the background of a Kerr-AdS black holes. The system exhibits the expected focussing of jets towards the impact parameter plane. We put forward that we can use the connection between this focussing behavior and the angular momentum induced pressure gradient to extrapolate the pressure gradient correction to the drag force that can be used for transverse elliptic flow in realistic RHIC. The result is recognizable as a relativistic pressure gradient force.

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