Holographic Brownian motion at finite density

Banerjee, Pinaki

doi:10.1103/physrevd.94.126008

Cited by 23 publications

(33 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The applicability of our effective theory framework to the scenario where the bath is chaotic and strongly coupled implies that it may be possible to construct a holographic dual description [61][62][63][64][65][66][67][68][69] of the particle's non-linear dynamics. The OTO extension of this nonlinear dynamics may be useful in determining a holographic prescription for computing the particle's OTOCs [67,70].…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Out of time ordered effective dynamics of a quartic oscillator

Chakrabarty

Chaudhuri

2019

SciPost Phys.

View full text Add to dashboard Cite

We study the dynamics of a quantum Brownian particle weakly coupled to a thermal bath. Working in the Schwinger-Keldysh formalism, we develop an effective action of the particle up to quartic terms. We demonstrate that this quartic effective theory is dual to a stochastic dynamics governed by a non-linear Langevin equation. The Schwinger-Keldysh effective theory, or the equivalent non-linear Langevin dynamics, is insufficient to determine the out of time order correlators (OTOCs) of the particle. To overcome this limitation, we construct an extended effective action in a generalised Schwinger-Keldysh framework. We determine the additional quartic couplings in this OTO effective action and show their dependence on the bath's 4-point OTOCs. We analyse the constraints imposed on the OTO effective theory by microscopic reversibility and thermality of the bath. We show that these constraints lead to a generalised fluctuation-dissipation relation between the non-Gaussianity in the distribution of the thermal noise experienced by the particle and the thermal jitter in its damping coefficient. The quartic effective theory developed in this work provides extension of several results previously obtained for the cubic OTO dynamics of a Brownian particle. Contents SciPost PhysicsSubmission [22,[27][28][29]. Nevertheless, it is interesting to explore the corrections to this effective dynamics by including the cubic and higher degree terms in the analysis. A simple way to obtain such corrections is to extend the Caldeira-Leggett model by introducing a non-linear combination of the bath oscillators' positions in the operator that couples to the particle [29,30].One such extension was discussed in [30] where the oscillators in the bath were divided into two sets (labelled by X and Y). Then apart from the bilinear interactions (which are present in the Caldeira-Leggett model), small cubic interactions were introduced between the particle (q) and pairs of bath oscillators. Each such pair consisted of one oscillator drawn from the set X and the other from the set Y. Due to these cubic interactions, this model was called the 'qXY model'.Introduction of these cubic interactions leads to cubic and higher degree terms in the effective action of the particle. In [30], this effective theory was studied up to the cubic terms in a Markovian limit. It was shown to be dual to a non-linear Langevin dynamics which has perturbative corrections over the linear Langevin dynamics in the Caldeira-Leggett model. The additional parameters in this non-linear dynamics receive contributions from the 3-point correlators of the bath. These 3-point correlators lead to an anharmonicity in the particle's dynamics and a non-Gaussianity in the distribution of the thermal noise experienced by the particle. In addition, they also give rise to thermal jitters 1 in both the frequency and the damping of the particle. The thermal jitter in the damping coefficient and the non-Gaussianity in the noise are connected by a generalised fluctuation-dissipation relation [30...

show abstract

Section: Conclusion and Discussionmentioning

confidence: 99%

Out of time ordered effective dynamics of a quartic oscillator

Chakrabarty

Chaudhuri

2019

SciPost Phys.

View full text Add to dashboard Cite

show abstract

“…In addition to the works already mentioned [21]- [35], the drag/diffusion quark analysis has been used to extract qualitative phenomenological information for the momentum broadening of heavy quarks moving in the quark-gluon plasma also for example in [46,47,48,49], while other works on Lifshitz-related spacetimes include [50,51,52,53,54]. and there is always a crossover region for ν = 1 which defines the type of growth.…”

Section: Introductionmentioning

confidence: 99%

Quantum fluctuation and dissipation in holographic theories: A unifying study scheme

Giataganas

Lee

Yeh

2018

J. High Energ. Phys.

View full text Add to dashboard Cite

Motivated by the wide range of applicability of the fluctuation and dissipation phenomena in non-equilibrium systems, we provide a universal study scheme for the dissipation of the energy and the corresponding Brownian motion analysis of massive particles due to quantum and thermal fluctuations in a wide class of strongly coupled quantum field theories. The underlying reason for the existence of such unified study scheme, is that our analytic methods turn out to heavily depend on the order of the Bessel functions ν, describing the string fluctuations attached to the particle. Different values of the order are associated to different theories.The two-point function of the fluctuations exhibits two different late time behaviors, depending purely on the value of the order of Bessel functions. We then find that the coefficients and observables associated with the stochastic motion at zero and finite temperature, depend on the scales of the theory through powers of the order ν. Moreover, the fluctuation-dissipation theorem is verified from the bulk perspective to be universally satisfied for the whole class of theories. Finally, we show that the analysis of certain types of Dp-brane fluctuations can be mapped one-to-one to the string fluctuations and therefore the stochastic brane observables can be read from the string ones. In the closing remarks we demonstrate how our analysis accommodates known results as special cases and provide more applications.

show abstract

“…PVs with OAM have been extensively created [12][13][14][15][16][17][18][19] and applied [20][21][22][23][24][25], but measurement techniques are still in their infancy [26]. In contrast, OAM has been measured qualitatively using mode sorters for Laguerre-Gaussian and helical beams [27][28][29][30], extended to radial modes [31,32], with adapted approaches to find the mode indices for Bessel-Gaussian [33][34][35] and Hermite-Gaussian modes [36].…”

mentioning

confidence: 99%

Quantitative orbital angular momentum measurement of perfect vortex beams

2019

View full text Add to dashboard Cite

Perfect (optical) vortices (PVs) have the mooted ability to encode orbital angular momentum (OAM) onto the field within a well-defined annular ring. Although this makes the near-field radial profile independent of OAM, the far-field radial profile nevertheless scales with OAM, forming a Bessel structure. A consequence of this is that quantitative measurement of PVs by modal decomposition has been thought to be unviable. Here, we show that the OAM content of a PV can be measured quantitatively, including superpositions of OAM within one perfect vortex. We outline the theory and confirm it by experiment with holograms written to spatial light modulators, highlighting the care required for accurate decomposition of the OAM content. Our work will be of interest to the large community who seek to use such structured light fields in various applications, including optical trapping and tweezing, and optical communication.

show abstract

Holographic Brownian motion at finite density

Cited by 23 publications

References 49 publications

Out of time ordered effective dynamics of a quartic oscillator

Out of time ordered effective dynamics of a quartic oscillator

Quantum fluctuation and dissipation in holographic theories: A unifying study scheme

Quantitative orbital angular momentum measurement of perfect vortex beams

Contact Info

Product

Resources

About