Publications

@article{sahoo1,
title = {Ageing in mixed populations of Stuart–Landau oscillators: the role of diversity},
author = {S Sahoo and V Varshney and A Prasad and R. Ramaswamy},
url = {https://iopscience.iop.org/article/10.1088/1751-8121/ab4a21},
doi = {10.1088/1751-8121/ab4a21},
issn = {1751-8121},
year = {2019},
date = {2019-10-21},
journal = {Journal of Physics A: Mathematical and Theoretical},
volume = {52},
pages = {464001},
abstract = {The phenomenon of ageing in a population of autonomous oscillators, namely the increase in the number of inactive (or non-oscillatory) units due to coupling interactions is studied in a population of globally coupled Stuart–Landau oscillators. The initial populations are prepared either as a mixture of active and inactive oscillators or as an ensemble of active oscillators with a mixture of distinct frequencies. The ageing transition does not depend on whether the coupling breaks gauge symmetry or not, but is affected by the degree of diversity in the ensemble, namely the existence of different types of subsystems that can cause oscillation quenching when coupled. The scaling exponents depend on the nature of the coupling interaction.},
keywords = {ageing, phase transition, scaling, stasis},
pubstate = {published},
tppubtype = {article}
}

@article{Tadi´c1992,
title = {Scaling behaviour in disordered sandpile automata},
author = {B Tadi´c, U Nowak, K Usadel, R Ramaswamy and S Padlewski
},
url = {https://link.aps.org/doi/10.1103/PhysRevA.45.8536},
doi = {10.1103/PhysRevA.45.8536},
year = {1992},
date = {1992-06-01},
journal = {Physical Review A},
volume = {45},
number = {12},
pages = {8536–8545},
abstract = {We study numerically the scaling behavior of disordered sandpile automata with preferred direction on a two-dimensional square lattice. We consider two types of bulk defects that modify locally the dynamic rule: (i) a random distribution of holes, through which sand grains may leave the system, and (ii) several models with a random distribution of critical heights. We find that at large time and length scales the self-organized critical behavior, proved exactly in the pure model, is lost for any finite concentration of defects both in the model of random holes and in those models of random critical heights in which the dynamic rule violates the height conservation law. In the case of the random critical height model with the height-conserving dynamics, we find that self-organized criticality holds for the entire range of concentrations of defects, and it belongs to the same universality class as the pure model. In the case of random holes we analyze the scaling properties of the probability distributions P(T,p,L) and D(s,p,L) of avalanches of duration larger than T and size larger than s, respectively, at lattices with linear size L and concentration of defect sites p. We find that in general the following scaling forms apply: P(T)=
T
−
α
scrP(T/x,T/L) and D(s)=
s
−
τ
scrD(s/m,s/
L
ν
), where x≡x(p) and m≡m(p) are the characteristic duration (length) and the characteristic size (mass) of avalanches for a given concentration of defects.

The power-law behavior of the distributions still persists for length scales T≪x(p) and mass scales s≪m(p). The characteristic length x(p) and mass m(p) are finite for small concentrations of defects and diverge at p→0 according to the power law x(p)∼
p
−
μ
x
and m(p)∼
p
−
μ
m
, with the numerically determined values of the exponents close to
μ
x
=1 and
μ
m
=1.5. The finite size of the lattice may affect the measured probability distributions if for a given concentration of defects the characteristic length x(p) exceeds the lattice size L. A finite-size scaling analysis for the mass distribution yields the exponent ν=1.5, while the duration of the avalanches scales linearly with the size. We also determine the exponent D=1.5 that connects the mass and the duration of avalanches.},
keywords = {Criticality, Fractals, Sandpile, scaling},
pubstate = {published},
tppubtype = {article}
}

@article{Sinha1987,
title = {Scaling of moments in rotational inelasticity},
author = {Sudeshna Sinha and Ramakrishna Ramaswamy},
url = {https://ramramaswamy.org/papers/030.pdf},
doi = {10.1016/0009-2614(87)87235-4},
issn = {00092614},
year = {1987},
date = {1987-01-01},
journal = {Chemical Physics Letters},
volume = {135},
number = {1-2},
pages = {153–158},
abstract = {We report the scaling behaviour of rotational energy transfer moments. The quantum moments exhibit a polynomial scaling behaviour in the variable ji(ji+1), whereas the classical moments scale as a polynomial in Ji2, whereJi is the initial rotational quantum number or action. Applications are made to Li*2-rare gas collisions, as well as to a classical planar-rotor collision model. The scaling theory allows an accurate interpolation and extrapolation of experimental scattering data. textcopyright 1987.},
keywords = {Inelasticity, scaling},
pubstate = {published},
tppubtype = {article}
}

@article{Bhargava1985,
title = {Quantum infomation from classical trajectories: Scaling deconvolution of moments in diatom-diatom collisions},
author = {Rajeev Bhargava and Ramakrishna Ramaswamy},
url = {https://ramramaswamy.org/papers/026.pdf},
doi = {10.1016/0301-0104(85)80077-X},
issn = {03010104},
year = {1985},
date = {1985-01-01},
journal = {Chemical Physics},
volume = {95},
number = {2},
pages = {253–261},
abstract = {An inversion procedure to obtain quantal transition probabilities from the analysis of classical moments has been applied to various model diatom-diatom collision systems. This inversion relies on the use of a scaling theory to analyse classical moments and the subsequent use of a quantal scaling theory in interpretation of the classical scaling coefficients. We obtain transition probabilities that are in good agreement with exact quantum studies, and also compare favorably with other moment inversion schemes that have been described earlier in the literature. textcopyright 1985.},
keywords = {Quantum Information, scaling},
pubstate = {published},
tppubtype = {article}
}

@article{Ramaswamy1984z,
title = {Classical trajectory analysis in atom-triatom collisions: Continuous quantization and scaling behaviour},
author = {Ramakrishna Ramaswamy},
url = {https://ramramaswamy.org/papers/021.pdf},
year = {1984},
date = {1984-01-01},
journal = {Chemical Physics},
volume = {88},
pages = {7-16},
keywords = {Collision Dynamics, Quantization, scaling},
pubstate = {published},
tppubtype = {article}
}

@article{Ramaswamy1984y,
title = {Collision dynamics of non-integrable systems: Validity of classical scaling},
author = {Ramakrishna Ramaswamy},
url = {https://ramramaswamy.org/papers/022.pdf},
year = {1984},
date = {1984-01-01},
journal = {Chemical Physics},
volume = {88},
pages = {17-25},
keywords = {Collision Dynamics, scaling},
pubstate = {published},
tppubtype = {article}
}

@article{DePristo1981z,
title = {Concerning the scaling behaviour in the classical mechanics of non-reactive collisions: An analytic investigation},
author = {Andrew DePristo and Ramakrishna Ramaswamy},
url = {https://ramramaswamy.org/papers/017.pdf},
year = {1981},
date = {1981-01-01},
journal = {Chemical Physics},
volume = {57},
pages = {129-140},
keywords = {Collision Dynamics, scaling},
pubstate = {published},
tppubtype = {article}
}

@article{Ramaswamy1980z,
title = {Dynamics of van der Waals molecules: A scaling theoretical analysis of I2*He},
author = {Ramakrishna Ramaswamy and Andrew E DePristo},
url = {https://ramramaswamy.org/papers/010.pdf},
doi = {10.1063/1.438915},
year = {1980},
date = {1980-01-01},
journal = {J. Chem. Phys.},
volume = {72},
number = {1},
pages = {770},
keywords = {molecular dynamics, scaling},
pubstate = {published},
tppubtype = {article}
}

@article{Ramaswamy1979z,
title = {On the correlation of rotationally inelastic rates: A scaling theoretical analysis},
author = {R Ramaswamy and A E Z Depristo and H Rabitz},
url = {https://ramramaswamy.org/papers/009.pdf},
year = {1979},
date = {1979-01-01},
journal = {Chem. Phys. Lett.},
volume = {61},
number = {3},
pages = {495–497},
keywords = {Inelasticity, molecular dynamics, scaling},
pubstate = {published},
tppubtype = {article}
}