arXiv subjects

Subhankar Roy

Publications and source records attributed to Subhankar Roy.

64 records · Page 4Linked to original sources

arXiv2019

Regularized Evolutionary Algorithm for Dynamic Neural Topology Search

Designing neural networks for object recognition requires considerable architecture engineering. As a remedy, neuro-evolutionary network architecture search, which automatically searches for optimal network architectures using evolutionary algorithms, has recently become very popular. Although very effective, evolutionary algorithms rely heavily on having a large population of individuals (i.e., network architectures) and is therefore memory expensive. In this work, we propose a Regularized Evolutionary Algorithm with low memory footprint to evolve a dynamic image classifier. In details, we introduce novel custom operators that regularize the evolutionary process of a micro-population of 10 individuals. We conduct experiments on three different digits datasets (MNIST, USPS, SVHN) and show that our evolutionary method obtains competitive results with the current state-of-the-art.

cs.NE↗

arXiv2018

Stability of neutrino parameters and self-complementarity relation with varying SUSY breaking scale

The scale at which supersymmetry (SUSY) breaks ($m_{s}$) is still unknown. The present article, following a top-down approach, endeavors to study the effect of varying $m_s$ on the radiative stability of the observational parameters associated with the neutrino mixing. These parameters get additional contributions in the minimal supersymmetric model,(MSSM). A variation in $m_s$ will influence the bounds for which the Standard Model,(SM) and MSSM work and hence will account for the different radiative contributions received from both sectors respectively, while running the renormalization group equations,(RGE). The present work establishes the invariance of the self complementarity relation among the three mixing angles, $θ_{13}+θ_{12}\approxθ_{23}$ against the radiative evolution. A similar result concerning the mass ratio, $m_2: m_1$ is also found to be valid. In addition to varying $m_s$, the work incorporates a range of different seesaw\,(SS) scales and tries to see how the latter affects the parameters.

hep-ph↗

arXiv2016

Generating nonzero $θ_{13}$ without breaking the $2$-$3$ symmetry of neutrino mass matrix

The prediction of vanishing reactor angle was thought to be a signature of $2$-$3$ symmetry of neutrino mass matrix. But the present study addresses certain interesting facts related with $2$-$3$ symmetry which are not addressed so far. The investigation highlights that $θ_{13}=0$, corresponds to a very special case in association with $2$-$3$ symmetry and to engender a non-zero $θ_{13}$, the breakdown of $2$-$3$ symmetry is not essential.

hep-ph↗

arXiv2016

Modulated bimaximal neutrino mixing

The present article is an endeavor to look into some fruitful frameworks based on "Bi-maximal" neutrino mixing, from a model independent stand. The possibilities involving the correction or attenuation of the original BM mixing matrix, followed by GUT-inspired charged lepton correction are invoked. The "symmetry-basis" thus constructed, accentuates some interesting facets such as: a modified QLC relation, $θ_{12}+θ_{c}\approx\fracπ{4}-θ_{13}\cos(nπ-δ_{CP})$, a possible link up between neutrino and charged lepton sectors, $θ_{13}^ν=θ_{12}^{l}\sim\mathcal{O}(θ_{C})$ or that between neutrinos and quarks, $θ_{13}^ν=θ_{C}$. The study vindicates the relevance of the Bi-maximal mixing as a first approximation.

hep-ph↗

arXiv2016

The mixing angle as a function of neutrino mass ratio

In the quark sector, we experience a correlation between the mixing angles and the mass ratios. A partial realization of the similar tie-up in the neutrino sector helps to constrain the parametrization of masses and mixing, and hints for a predictive framework. We derive five hierarchy dependent textures of neutrino mass matrix with minimum number of parameters ($\leq\,4$), following a model-independent strategy.

hep-ph↗

arXiv2013

Leptonic mixing matrix in terms of Cabibbo angle

We phenomenologically build a neutrino mass matrix obeying $μ-τ$ symmetry with only two parameters, Cabibbo angle $(λ)$ and a flavour twister parameter $(η)$. For vanishing $η$, the model assumes TBM mixing. When $η=λ$, the model generates a solar mixing angle and solar mass squared difference that coincide with the experimental best-fits. It motivates us to propose a mixing matrix in the neutrino sector with $ sinθ_{12}<\frac{1}{\sqrt{3}}$, $θ_{13}=0$ and $θ_{23}=π/4$. The corrections in $θ_{13}$ and $θ_{23}$ are conducted following the breaking of $μ-τ$ symmetry, by choosing a proper unitary diagonalizing charged lepton matrix, and this ensures that $θ_{23}$ lies within the first octant. The Cabibbo angle $(λ=\sinθ_{c})$ plays the role of a guiding parameter in both neutrino as well as leptonic sector. The effect of the Dirac CP violating phase $δ_{cp}$ is also studied when it enters either through the charged lepton diagonalizing matrix or through neutrino mixing matrix.

hep-ph↗

arXiv2012

Bi-Large neutrino mixing with charged lepton correction

The usual Bi-Maximal (BM) neutrino mixing faces an inherent problem in lowering the solar mixing angle below $\tan^{2}θ_{12}=0.50$ when charged lepton correction is taken. This minimum $θ_{12}$ is achievable only if CP violation is absent. We start with a new model which incorporates a new idea of mixing developed recently, called Bi-Large (BL) mixing, similar to BM mixing execpt that the former chooses rather $θ_{13}$ as Cabibbo angle $(θ_c)$ than zero. We apply this mixing in the neutrino sector, followed by a charged lepton correction with the CKM type matrix $U_{l}$. This model marks a prediction on $θ_{23}$ to lie within the first octant. The CP violating phase $δ_{CP}$ dictates the prediction of all the three mixing angles. A proper choice of $δ_{CP}$ leads to the predictions of all the three mixing angles including $θ_{12}$, to align very precisely with the experimental bestfits. This close agreement thus hoists Bi-Large mixing as an important and promising mixing scheme, in contrast to BM or TBM mixing as a first approximation. A formal derivation of BL mixing from discrete symmetry will be an important investigation in neutrino physics.

hep-ph↗

arXiv2012

An Efficient Biological Sequence Compression Technique Using LUT And Repeat In The Sequence

Data compression plays an important role to deal with high volumes of DNA sequences in the field of Bioinformatics. Again data compression techniques directly affect the alignment of DNA sequences. So the time needed to decompress a compressed sequence has to be given equal priorities as with compression ratio. This article contains first introduction then a brief review of different biological sequence compression after that my proposed work then our two improved Biological sequence compression algorithms after that result followed by conclusion and discussion, future scope and finally references. These algorithms gain a very good compression factor with higher saving percentage and less time for compression and decompression than the previous Biological Sequence compression algorithms. Keywords: Hash map table, Tandem repeats, compression factor, compression time, saving percentage, compression, decompression process.

cs.CE↗

arXiv2012

Expansion of $U_{PMNS}$ and Neutrino mass matrix $M_ν$ in terms of $sinθ_{13}$ for Inverted Hierarchical case

The recent observational data supports the deviation from Tri-bimaximal (TBM) mixings. Different neutrino mass models suggest the interdependency among the observational parameters involving the mixing angles. On phenomenological ground we try to construct the PMNS matrix $U_{PMNS}$ with certain analytic structure satisfying the unitary condition, in terms of a single observational parameter $sinθ_{13}$. We hypothesise the three neutrino masses $m_{i}$ as functions of $sinθ_{13}$ and then construct the neutrino mass matrix $M_ν$. We assume the convergence of the model to TBM mixing when $θ_{13}$ is taken zero. This mass matrix so far obtained can be employed for various applications including the estimation of matter-antimatter asymmetry of the Universe.

hep-ph↗

arXiv2012

A new method of parametrisation of neutrino mass matrix through breaking of $μ-τ$ symmetry: Normal hierarchy

In the first part of the present work the $μ-τ$ symmetry of the neutrino mass matrix is perturbed at its minimal level in order to produce deviation from Tri-bimaximal mixing (TBM), which includes nonzero value of reactor angle $θ_{13}$ and maximal condition of $\tan^{2}θ_{23}=1$. The parametrisation of neutrino mass matrix which describes Normal hierarchy (NH), has been addressed with minimum number of independent parameters, out of which two parameters $η$ and $α$ take care of $θ_{12}$ and $θ_{13}$ respectively without any interference with mass eigenvalues. In the second part the deviation from maximal condition $\tan^{2}θ_{23}=1$, along with the nonzero value of $θ_{13}$, has been implemented with the introduction of a perturbing matrix which breaks the $μ-τ$ symmetric mass matrix. The model is found to be flexible enough to adjust itself with the changing precise experimental results. The method is also applicable for inverted hierarchy and quasi-degenerate cases.

hep-ph↗