arXiv subjects

Amit Kr. Chattopadhyay

Publications and source records attributed to Amit Kr. Chattopadhyay.

4 recordsLinked to original sources

arXiv2000

Non-equilibrium growth for a restricted-curvature model

The static and dynamic roughenings of a growing crystalline facet is studied where the growth mechanism is controlled by a restricted-curvature (RC) geometry. A continuum equation, in analogy with the Kardar-Parisi-Zhang (KPZ) equation is considered for the purpose. It is shown here that although the growth process begins with a RC geometry, a structural phase transition occurs from the restricted-curvature phase to the KPZ phase. An estimation of the corresponding critical temperature is given here. Calculations on the static phase transition give results along the same line as existing predictions, apart fromm minor numerical adjustments.

cond-mat.stat-mech↗

arXiv1999

Coupled non-equilibrium growth equations: Self-consistent mode coupling using vertex renormalization

We find that studying the simplest of the coupled non-equilibrium growth equations of Barabasi by self-consistent mode coupling requires the use of dressed vertices. Using the vertex renormalization, we find a roughness exponent which already in the leading order is quite close to the numerical value.

physics.flu-dyn↗

arXiv1999

Wall bounded turbulent shear flow: Analytic result for an universal amplitude

In the turbulent boundary layer above a flat plate, the velocity profile is known to have the form v=v_0[(1/κ) ln z + constant]. The distance from the wall in dimensionless units is z and v_0 is an uniquely defined velocity scale. The number κis universal and measurements over several decades have shown that it is nearly 0.42. We use a randomly stirred model of turbulence to derive the above law and find κ=\sqrt{\frac{108} {125 π}} \simeq 0.52.

cond-mat.stat-mech↗

arXiv1999

The Non-local Kardar-Parisi-Zhang Equation With Spatially Correlated Noise

The effects of spatially correlated noise on a phenomenological equation equivalent to a non-local version of the Kardar-Parisi-Zhang equation are studied via the dynamic renormalization group (DRG) techniques. The correlated noise coupled with the long ranged nature of interactions prove the existence of different phases in different regimes, giving rise to a range of roughness exponents defined by their corresponding critical dimensions. Finally self-consistent mode analysis is employed to compare the non-KPZ exponents obtained as a result of the long range -long range interactions with the DRG results.

cond-mat.stat-mech↗