arXiv subjects

Manoranjan Samal

Publications and source records attributed to Manoranjan Samal.

8 recordsLinked to original sources

arXiv2025

Investigating (Non)-Integrability and Pulsating String in D3-Brane Background

This work explores the (non)-integrability and chaotic dynamics of classical strings in the background of a D3-brane with a non-commutative parameter, within the framework of the AdS/CFT correspondence. Using the Polyakov action, we derive the equations of motion and constraints for pulsating strings and analyze their stability through perturbation theory. In the high-energy limit, the first-order perturbed equation simplifies to the P\"oschl-Teller equation, solvable via associated Legendre or hypergeometric functions, while numerical methods are employed for generic energy values. We demonstrate that the non-commutative parameter enhances chaotic behavior, as evidenced by the Largest Lyapunov Exponent (LLE). Furthermore, we investigate the integrability of geodesic motion and identify two distinct string modes: captured at and escape to infinity. Finally, we study pulsating strings in the deformed $(AdS_{3} \times S^{2})_{\varkappa}$ background, deriving dispersion relations for both short and long strings.

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arXiv2024

Pulsating string solution and stability in two parameter $\chi$-deformed background

In this paper, we investigate pulsating string solutions within the context of a two-parameter $\chi$-deformed $\mathcal{R} \times S^2$ background. We derive the energy and oscillation number relation for the deformed $\mathcal{R} \times S^2$ in a short string limit. Additionally, we derive the first-order perturbation equation for a pulsating string in this specific background. As a special case of the two-parameter deformed background, we examine the stability of the pulsating string solution in one-parameter deformed $\mathcal{R} \times S^2$ and $AdS_3$ background by setting one of the deformation parameters to zero.

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arXiv2018

Perturbations of Pulsating Strings

We discuss semiclassical quantization of circular pulsating strings in AdS3 x S3 background with and without the Neveu-Schwarz- Neveu-Schwarz (NS-NS) flux. We find the equations of motion corresponding to the quadratic action in bosonic sector in terms of scalar quantities and invariants of the geometry. The general equations for studying physical perturbations along the string in an arbitrary curved spacetime are written down using covariant formalism. We discuss the stability of these string configurations by studying the solutions of the linearized perturbed equations of motion.

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arXiv2018

Finite Size Effect from Classical Strings in deformed AdS$_3\times$ S$^3$

We study the finite size effect of rigidly rotating and spinning folded strings in $(AdS_3\times S^3)_{\varkappa}$ background. We calculate the leading order exponential corrections to the infinite size dispersion relation of the giant magnon, and single spike solutions. For the spinning folded strings we write the finite size effect in terms of the known Lambert $W$-function.

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arXiv2018

Spinning pulsating strings in $(AdS_5 \times S^5)_{\varkappa}$

We study a general class of spinning pulsating strings in $(AdS_5 \times S^5)_{\varkappa}$ background. For these family of solitons, we examine the scaling relation between the energy, spin or angular momentum. We verify that in $\varkappa \rightarrow 0 $ limit these relations reduce to the undeformed $AdS_5 \times S^5$ case. We further study an example of a string which is spinning in the $\varkappa$-deformed AdS$_5$ and S$^5$ simultaneously and find out the scaling relation among various conserved charges.

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arXiv2016

Chaos in classical string dynamics in $\hatγ$ deformed $AdS_5 \times T^{1,1}$

We consider a circular string in $\hatγ$ deformed $AdS_5 \times T^{1,1}$ which is localized in the center of $AdS_5$ and winds around the two circles of deformed $T^{1,1}$. We observe chaos in the phase space of the circular string implying non-integrability of string dynamics. The chaotic behaviour in phase space is controlled by energy as well as the deforming parameter $\hatγ$. We further show that the point like object exhibits non-chaotic behaviour. Finally we calculate the Lyapunov exponent for both extended and point like object in support of our first result.

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arXiv2015

A note on oscillating strings in $AdS_3 \times S^3$ with mixed three-form fluxes

We present a detailed study of the pulsating string solutions in AdS3 x S3 supported by both RR and NS-NS fluxes. This background has recently been proved to be integrable. We find the dispersion relation between the energy, oscillation number and other conserved charges when the NS-NS flux turned on is small. We further discuss the fate of the string solutions in pure RR and NS-NS cases.

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arXiv2014

Pulsating strings on $(AdS_3 \times S^3)_\varkappa$

We derive the energy of pulsating strings as a function of adiabatic invariant oscillation number, which oscillates in $S^2_{\varkappa}$. We find similar solutions for the strings oscillating in deformed $AdS_3$. Furthermore, we generalize the result to the oscillating strings in anti-de Sitter space in the presence of extra angular momentum in $(AdS_3 \times S^1)_\varkappa$.

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