Results for "Surjeet Singh"

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Finite-size effects in the quasi-one-dimensional quantum magnets Sr$_{2}$CuO$_{3}$, Sr$_{2}$Cu$_{0.99}$M$_{0.01}$O$_{3}$ (M = Ni, Zn), and SrCuO$_{2}$Jan 10 2015Jun 17 2015We studied the finite-size effects on the magnetic behavior of the quasi-one-dimensional spin S = $\frac{1}{2}$ Heisenberg antiferromagnets Sr$_{2}$CuO$_{3}$, Sr$_{2}$Cu$_{0.99}$M$_{0.01}$O$_{3}$ (M = Zn and Ni), and SrCuO$_{2}$. Magnetic susceptibility ... More
Magnetic ordering of Mn sublattice, dense Kondo lattice behavior of Ce in (RPd3)8Mn (R = La, Ce)Apr 02 2003We have synthesized two new interstitial compounds (RPd3)8Mn (R = La and Ce). The Mn ions present in "dilute" concentration of just 3 molar percent form a sublattice with an unusually large Mn-Mn near neighbor distance of ~ 85 nm. While the existence ... More
Rings of Invariant Module Type and Automorphism-Invariant ModulesJul 23 2012A module is called automorphism-invariant if it is invariant under any automorphism of its injective hull. In [Algebras for which every indecomposable right module is invariant in its injective envelope, Pacific J. Math., vol. 31, no. 3 (1969), 655-658] ... More
Simultaneous behaviour of the Fourier coefficients of two Hilbert modular cusp formsMay 01 2018In this article, we study the simultaneous sign changes of the Fourier coefficients of two Hilbert cusp forms of different integral weights. We also study the simultaneous non-vanishing of Fourier coefficients, of two distinct non-zero primitive Hilbert ... More
Rings and modules which are stable under automorphisms of their injective hullsJan 24 2013It is proved, among other results, that a prime right nonsingular ring (in particular, a simple ring) $R$ is right self-injective if $R_R$ is invariant under automorphisms of its injective hull. This answers two questions raised by Singh and Srivastava, ... More
On the gaps between non-zero Fourier coefficients of eigenforms with CMAug 15 2016Suppose $E$ is an elliptic curve over $\mathbb{Q}$ of conductor $N$ with complex multiplication (CM) by $\mathbb{Q}(i)$, and $f_E$ is the corresponding cuspidal Hecke eigenform in $S^{\mathrm{new}}_2(\Gamma_0(N))$. Then $n$-th Fourier coefficient of $f_E$ ... More
High temperature linear magnetoresistance and scaling behavior in the Ba(Fe${_{1-x}}$Co${_{x}}$)$_{2}$As$_{2}$ seriesJan 11 2018We present magnetotransport studies of the parent, an underdoped and an optimally doped composition of the Ba(Fe${_{1-x}}$Co${_{x}}$)${_{2}}$As${_{2}}$ series. We observe that both the Kohler's and modified Kohler's scaling is typically violated in both ... More
Crystal growth of the non-magnetic Zn$^{2+}$ and magnetic Co$^{2+}$ doped quasi one-dimensional spin chain compound SrCuO$_{2}$ using the travelling solvent floating zone methodJan 10 2015We report on the crystal growth of the quasi one-dimensional quantum spin chain compound SrCuO$_{2}$ and its doped variants containing magnetic cobalt (0.25%, 0.5%, 1% and 2.5%) and non-magnetic zinc (0.5\% and 1\%) impurities. Crystals are grown using ... More
CeMnNi4: A soft ferromagnet with a high degree of transport spin polarizationSep 05 2005Oct 20 2005In this letter we introduce a new soft ferromagnetic compound, i.e. CeMnNi4, which exhibits a large moment (~4.95mu_B/Mn) and high degree of spin polarization. The system has a ferromagnetic transition temperature of 148K. Isothermal magnetization measurements ... More
Excess speicific heat of the gapped sliding phonons in the incommensurate composite crystal Sr$_{14}$Cu$_{24}$O$_{41}$Aug 02 2018Aug 03 2018We show that low temperature specific heat (C$_p$) of the incommensurate chain-ladder system Sr$_{14}$Cu$_{24}$O$_{41}$ is enriched by the presence of a rather large excess contribution of non-magnetic origin. Diluted Al doping at the Cu site or annealing ... More
Impurities in weakly coupled quantum spin chains Sr$_{2}$CuO$_{3}$ and SrCuO$_{2}$Jun 05 2017We study the effect of non-magnetic Zn$^{2+}$ (spin-$0$) and magnetic Ni$^{2+}$ (spin-$1$) impurities on the ground state and low-lying excitations of the quasi-one-dimensional spin-$1/2$ Heisenberg antiferromagnet Sr$_{2}$CuO$_{3}$ using inelastic neutron ... More
Dilute stuffing in the pyrochlore iridate $Eu_2Ir_2O_7$May 04 2018The pyrochlore Eu$_2$Ir$_2$O$_7$ has recently attracted significant attention as a candidate Weyl semimetal. The previous reports on this compound unanimously show a thermally induced metal to insulator (MI) transition, concomitant with antiferromagnetic ... More
Magnetic disorder and gap symmetry in optimally electron doped Sr(Fe, Co)$_2$As$_2$ superconductorAug 30 2017Aug 31 2017We investigate the magnetic pair-breaking due to Mn impurities in the optimally electron doped Sr(Fe$_{0.88} $Co$_{0.12} $)$_{2} $As$_2 $ superconductor to deduce the symmetry of the superconducting order parameter. Experiments on the as-grown crystals ... More
Equidistribution of signs for Hilbert modular forms of half-integral weightAug 18 2017Feb 22 2018We prove an equidistribution of signs for the Fourier coefficients of Hilbert modular forms of half-integral weight. Our study focuses on certain subfamilies of coefficients that are accessible via the Shimura correspondence. This is a generalization ... More
Ordered spin-ice state in the geometrically frustrated metallic-ferromagnet Sm2Mo2O7Jun 28 2007The recent discovery of Spin-ice is a spectacular example of non-coplanar spin arrangements that can arise in the pyrochlore A2B2O7 structure. We present magnetic and thermodynamic studies on the metallic-ferromagnet pyrochlore Sm2Mo2O7. Our studies, ... More
Anomalous lattice contraction and emergent electronic phases in Bi-doped Eu$_2$Ir$_2$O$_7$Feb 08 2019We study the pyrochlore series (Eu$_{1-x}$Bi$_x$)$_2$Ir$_2$O$_7$ for $ 0 \leq x \leq 1$. We show that for small $x$, the lattice undergoes an anomalous contraction but the all-in/all-out and metal-to-insulator transitions remain robust, and the resistivity ... More
Manifestation of geometric frustration on magnetic and thermodynamic properties of pyrochlores $Sm_2X_2O_7$ (X=Ti, Zr)Dec 18 2007We present here magnetization, specific heat and Raman studies on single-crystalline specimens of the first pyrochlore member $Sm_2Ti_2O_7$ of the rare-earth titanate series. Its analogous compound $Sm_2Zr_2O_7$ in the rare-earth zirconate series is also ... More
Study of CeNi4Mn by neutron diffractionOct 17 2006We report neutron diffraction measurements on CeNi4Mn, which has recently been identified as a soft ferromagnet (Tc ~ 140 K) with a sizeable spin-transport polarization. Our data show conclusively that the Mn atoms occupy a unique site (4c) in the unit ... More
Effects of quantum impurity spins on the magnetic properties of zigzag and linear spin chainsFeb 11 2016We investigated the magnetic ground state and low-energy excitations of the spin chains compounds SrCuO$_{2}$ (zigzag chains) and Sr$_{2}$CuO$_{3}$ (linear chains) in the presence of quantum impurities induced by lightly doping ($\leq 1 \%$) with Zn$^{2+}$ ... More
Effect of magnetic and non-magnetic impurities on the spin dimers in the spin 1/2 chains of quantum magnet Sr$_{14}$Cu$_{24}$O$_{41}$Aug 02 2018We study the effect of impurities on the two types of spin-dimers in the hybrid chain/ladder spin 1/2 quantum magnet Sr$_{14}$Cu$_{24}$O$_{41}$. Four different impurities were used, namely, the non-magnetic Zn (0.0025 and 0.01 per Cu) and Al (0.0025 and ... More
Single-crystal growth and magnetic properties of the metallic molybdate pyrochlore Sm2Mo2O7Aug 24 2007We have successfully grown cm3-size single crystals of the metallic-ferromagnet Sm2Mo2O7 by the floating-zone method using an infrared-red image furnace. The growth difficulties and the remedies found using a 2-mirror image furnace are discussed. Magnetization ... More
On $n^{th}$ class preserving automorphisms of $n$-isoclinism familyJan 19 2017Let $G$ be a finite group and $M,N$ be two normal subgroups of $G$. Let $Aut_N^M(G)$ denote the group of all automorphisms of $G$ which fix $N$ element wise and act trivially on $G/M$. Let $n$ be a positive integer. In this article we have shown that ... More
Coupled antiferromagnetic-ferroelectric transition, higher compensation temperature and enhanced exchange bias in SmFeO3 nanoparticlesNov 09 2016In transition metal oxides, quantum confinement arising from a large surface to volume ratio often gives rise to novel physico-chemical properties at nanoscale. Their size dependent properties have potential applications in diverse areas, including therapeutics, ... More
Temperature dependent Raman and x-ray studies of spin-ice pyrochlore $Dy_2Ti_2O_7$ and non-magnetic pyrochlore $Lu_2Ti_2O_7$Nov 28 2008We present here temperature-dependent Raman, x-ray diffraction and specific heat studies between room temperature and 12 K on single crystals of spin-ice pyrochlore compound $Dy_2Ti_2O_7$ and its non-magnetic analogue $Lu_2Ti_2O_7$. Raman data show a ... More
Nanosize effect: Enhanced compensation temperature and existence of magneto-dielectric coupling in SmFeO3Nov 09 2016Jun 29 2017In transition metal oxides, quantum confinement arising from a large surface to volume ratio often gives rise to novel physico-chemical properties at nanoscale. Their size dependent properties have potential applications in diverse areas, including therapeutics, ... More
A Resonant Mode for Gravitational Wave Detectors based on Atom InterferometryJun 06 2016We describe a new atom interferometric gravitational wave detector design that can operate in a resonant mode for increased sensitivity. By oscillating the positions of the atomic wavepackets, this resonant detection mode allows for coherently enhanced, ... More
Low temperature and high pressure Raman and x-ray studies of pyrochlore Tb$_2$Ti$_2$O$_7$ : phonon anomalies and possible phase transitionApr 23 2009We have carried out temperature and pressure-dependent Raman and x-ray measurements on single crystals of Tb$_2$Ti$_2$O$_7$. We attribute the observed anomalous temperature dependence of phonons to phonon-phonon anharmonic interactions. The quasiharmonic ... More
Highly tunable magnetic spirals and electric polarization in Gd$_{0.5}$Dy$_{0.5}$MnO$_3$Mar 05 2019Recent progress in the field of multiferroics led to the discovery of many new materials in which ferroelectricity is induced by cycloidal spiral orders. The direction of the electric polarization is typically constrained by spin anisotropies and magnetic ... More
Microcontroller Based Testing of Digital IP-CoreMay 09 2012Testing core based System on Chip is a challenge for the test engineers. To test the complete SOC at one time with maximum fault coverage, test engineers prefer to test each IP-core separately. At speed testing using external testers is more expensive ... More
Atmospheric muons charge ratio analysis at the INO-ICAL detectorSep 02 2017Jun 29 2018The proposed Iron Calorimeter (ICAL) detector at Indian Neutrino Observatory(INO) will be a large (50 kt) magnetized detector located 1270 m underground at Bodi West Hills in Tamilnadu. ICAL is capable of identifying the charge of the particles. In this ... More
Effect of genome sequence on the force-induced unzipping of a DNA moleculeMar 14 2006We considered a dsDNA polymer in which distribution of bases are random at the base pair level but ordered at a length of 18 base pairs and calculated its force elongation behaviour in the constant extension ensemble. The unzipping force $F(y)$ vs. extension ... More
Statistical Mechanics of thermal denaturation of DNA oligomersMay 07 2004Double stranded DNA chain is known to have nontrivial elasticity. We study the effect of this elasticity on the denaturation profile of DNA oligomer by constraining one base pair at one end of the oligomer to remain in unstretched (or intact) state. The ... More
Statistical Theory of Force Induced Unzipping of DNAMay 07 2004May 18 2005The unzipping transition under the influence of external force of a dsDNA molecule has been studied using the Peyrard-Bishop Hamiltonian. The critical force $F_c(T)$ is found to depend on the potential parameters $k$, represents the stiffness of single ... More
On Equality of Certain Automorphism GroupsMay 21 2015Jan 29 2016Let $G = H\times A$ be a group, where $H$ is a purely non-abelian subgroup of $G$ and $A$ is a non-trivial abelian factor of $G$. Then, for $n \geq 2$, we show that there exists an isomorphism $\phi : Aut_{Z(G)}^{\gamma_{n}(G)}(G) \rightarrow Aut_{Z(H)}^{\gamma_{n}(H)}(H)$ ... More
A Text to Speech (TTS) System with English to Punjabi ConversionNov 13 2014The paper aims to show how an application can be developed that converts the English language into the Punjabi Language, and the same application can convert the Text to Speech(TTS) i.e. pronounce the text. This application can be really beneficial for ... More
Super-Arrhenius behaviour of molecular glass formersFeb 02 2019A theory is developed to calculate values of the potential energy barriers to structural relaxation in molecular glass formers from the data of static pair correlation function. The barrier height is shown to increase due to increase in number of the ... More
Pulling short DNA molecules having defects on different locationsSep 28 2015We present a study on the role of defects on the stability of short DNA molecules. We consider short DNA molecules (16 base pairs) and investigate the thermal as well as mechanical denaturation of these molecules in the presence of defects that occurs ... More
Reusability Framework for Cloud ComputingOct 30 2012Cloud based development is a challenging task for several software engineering projects, especially for those which needs development with reusability. Present time of cloud computing is allowing new professional models for using the software development. ... More
Effect of defects on thermal denaturation of DNA OligomersMay 03 2001Aug 29 2001The effect of defects on the melting profile of short heterogeneous DNA chains are calculated using the Peyrard-Bishop Hamiltonian. The on-site potential on a defect site is represented by a potential which has only the short-range repulsion and the flat ... More
Design and Implementation of Bit Transition CounterFeb 11 2014In today VLSI system design, power consumption is gaining more attention as compared to performance and area. This is due to battery life in portable devices and operating frequency of the design. Power consumption mainly consists of static power, dynamic ... More
Phase diagram of mechanically stretched DNA: The salt effectSep 05 2014The cations, in form of salt, present in the solution containing DNA play a crucial role in the opening of two strands of DNA. We use a simple non linear model and investigate the role of these cations on the mechanical unzipping of DNA. The Hamiltonian ... More
Effect of salt concentration on the stability of heterogeneous DNASep 28 2015We study the role of cations on the stability of double stranded DNA (dsDNA) molecules.It is known that the two strands of double stranded DNA(dsDNA) have negative charge due to phosphate group. Cations in the form of salt in the solution, act as shielding ... More
Directional Detection of Dark Matter using Spectroscopy of Crystal DefectsMay 27 2017We propose a method to identify the direction of an incident Weakly Interacting Massive Particle (WIMP) via induced nuclear recoil. Our method is based on spectroscopic interrogation of quantum defects in macroscopic solid-state crystals . When a WIMP ... More
Unbiased Ratio-Type Estimator Using Transformed Auxiliary Variable In Negative Correlation CaseOct 06 2012The objective of this paper is to propose an unbiased ratio-type estimator for finite population mean when the variables are negatively correlated. Hartley and Ross[2] and Singh and Singh [6] estimators are identified as particular cases of the proposed ... More
Effect of Misconception on Transfer in Problem SolvingFeb 24 2016We examine the effect of misconceptions about friction on students' ability to solve problems and transfer from one context to another. We analyze written responses to paired isomorphic problems given to introductory physics students and discussions with ... More
Categorization of problems to assess and improve proficiency as teachers and learnersFeb 21 2016We describe how graduate students categorize introductory mechanics problems based on the similarity of their solutions. Graduate students were asked at the end of a teaching assistant training class to categorize problems from their own perspective and ... More
Assessing and improving student understanding of quantum mechanicsFeb 18 2016We developed a survey to probe student understanding of quantum mechanics concepts at the beginning of graduate instruction. The survey was administered to 202 graduate students in physics enrolled in first-year quantum mechanics courses from seven different ... More
What Can Learn from PER: Physics Education Research?Feb 20 2016I believe that most teachers develop a belief in a set of pedagogical practices. As we teach, we try different ways to teach topics and then judge how successful the methods were. After several years, we have a compilation of techniques in our teaching ... More
Improving Student Understanding of Coulomb's Law and Gauss's LawFeb 20 2016We discuss the development and evaluation of five research-based tutorials on Coulomb's law, superposition, symmetry and Gauss's Law to help students in the calculus-based introductory physics courses learn these concepts. We discuss the performance of ... More
Coupling Conceptual and Quantitative Problems to Develop Expertise in Introductory Physics StudentsFeb 20 2016We discuss the effect of administering conceptual and quantitative isomorphic problem pairs (CQIPP) back to back vs. asking students to solve only one of the problems in the CQIPP in introductory physics courses. Students who answered both questions in ... More
Rethinking Tools for Training Teaching AssistantsFeb 20 2016The ability to categorize problems is a measure of expertise in a domain. In order to help students learn effectively, instructors and teaching assistants (TAs) should have pedagogical content knowledge. They must be aware of the prior knowledge of students ... More
Quantum Mechanics and RealityDec 20 2004We begin by discussing ``What exists?'', i.e. ontology, in Classical Physics which provided a description of physical phenomena at the macroscopic level. The microworld however necessitates a introduction of Quantum ideas for its understanding. It is ... More
Homi Jehangir Bhabha : Architect of Modern Science and Technology in IndiaJun 18 2009After describing Bhabha's early life at Bombay, now Mumbai, we discuss his research career at Cambridge, where he made many distinguished contributions to positron physics, cosmic rays and the meson theory. These include theory of positron-electron scattering ... More
Einstein and the QuantumOct 24 2005We review here the main contributions of Einstein to the quantum theory. To put them in perspective we first give an account of Physics as it was before him. It is followed by a brief account of the problem of black body radiation which provided the context ... More
Holographic flows to IR Lifshitz spacetimesNov 29 2010Apr 27 2011Recently we studied `vanishing' horizon limits of `boosted' black D3-brane geometry \cite{hsnr}. The type IIB solutions obtained by taking these special double limits were found to describe nonrelativistic Lifshitz spacetimes at zero temperature. In the ... More
Galilean type IIA backgrounds and a mapJul 06 2010Jun 29 2011We obtain non-relativistic AdS4 X CP3 solutions with dynamical exponent 3 in type IIA string theory, both with and without Romans mass. The compactifications to four dimensions are found to describe Proca fields in anti-de Sitter spacetime. This leads ... More
M2-branes on a resolved $C_4/Z_4$Jul 31 2008Apr 02 2009We write down M2-branes on the resolved $C_4/Z_4$ orbifold space. The resolved spatial geometry is such that it interpolates between $R^2\times CP_3$ near the branes and $C_4/Z_4$ asymptotically. The near horizon geometry of these branes is a deformation ... More
Note on (D6,D8) Bound State, Massive Duality and Non-commutativityDec 10 2002Apr 26 2003In this paper we study half-supersymmetric (D6,D8) bound state brane configuration of massive type IIA supergravity. We show that this bound state can also be generated by using massive T-duality rules of type-II supergravities in D=9, starting from D7-branes. ... More
AdS Bubbles, E$p$-branes and EntanglementOct 15 2014The AdS-bubble solutions interestingly mimic Schr\"odinger-like geometries when expressed in light-cone coordinates. These D$p$ bubble vacuas exhibit asymmetric scaling property with a negative dynamical exponent of time $a<0$, but are smooth geometries. ... More
Plane Wave Type II$^*$ String BackgroundsMay 23 2004In this note we aim to study plane-wave limits of the solutions of type II$^*$ superstring theories. We consider Freund-Rubin type $dS_5\times H^5$ solutions of type IIB$^*$ theory and obtain a new kind of plane-wave solutions, we refer them as de Sitter ... More
Twisted Satake CategoryOct 31 2012Dec 06 2012We extend Bezrukavnikov and Finkelberg's description of the G(\C[[t]])-equivariant derived category on the affine Grassmannian to the twisted setting of Finkelberg and Lysenko. Our description is in terms of coherent sheaves on the twisted dual Lie algebra. ... More
Gravitational Collapse of Dark Energy Field ConfigurationsJul 29 2010It is now a well established fact based on several observations that we live in a Universe dominated by dark energy. The most natural candidates for dark energy are fields in curved space-time. We develop the formalism to study the gravitational collapse ... More
Gravitational Wave transient signal emission via Ekman Pumping in Neutron Stars during post-glitch relaxation phaseMay 26 2016Sep 05 2016Glitches in the rotational frequency of a spinning neutron star could be promising sources of gravitational wave signals lasting between a few {\mu}s to a few weeks. The emitted signals and their properties depend upon the internal properties of the neutron ... More
A small non-vanishing cosmological constant from vacuum energy: physically and observationally desirableDec 05 1994Dec 15 1995Increasing improvements in the independent determinations of the Hubble constant and the age of the universe now seem to indicate that we need a small non-vanishing cosmological constant to make the two independent observations consistent with each other. ... More
Classification of Homogeneous Fourier Matrices Associated with Modular DataOct 17 2016Modular data are commonly studied in mathematics and physics. A modular datum defines finite dimensional representations of the modular group $\mbox{SL}_2(\ZZ)$. For every Fourier matrix in a modular datum there exists a self-dual $C$-algebra. A Fourier ... More
Are loop quantum cosmos never singular?Jan 19 2009Apr 29 2009A unified treatment of all known types of singularities for flat, isotropic and homogeneous spacetimes in the framework of loop quantum cosmology (LQC) is presented. These include bangs, crunches and all future singularities. Using effective spacetime ... More
Implementing an intelligent version of the classical sliding-puzzle game for unix terminals using Golang's concurrency primitivesMar 28 2015Aug 22 2015An intelligent version of the sliding-puzzle game is developed using the new Go programming language, which uses a concurrent version of the A* Informed Search Algorithm to power solver-bot that runs in the background. The game runs in computer system's ... More
Curvature invariants, geodesics and the strength of singularities in Bianchi-I loop quantum cosmologyDec 29 2011Apr 11 2012We investigate the effects of the underlying quantum geometry in loop quantum cosmology on spacetime curvature invariants and the extendibility of geodesics in the Bianchi-I model for matter with a vanishing anisotropic stress. Using the effective Hamiltonian ... More
Partition function of a bubble formed in double stranded DNASep 09 2009We calculate the entropic part of partition function of a bubble embedded in a double stranded DNA (dsDNA) by considering the total weights of possible configurations of a system of two single stranded DNA (ssDNA) of given length which start from a point ... More
Subgroups of the additive group of real lineDec 26 2013May 20 2014Without assuming the field structure on the additive group of real numbers $\mathbb{R}$ with the usual order $<,$ we explore the fact that every proper subgroup of $\mathbb{R}$ is either closed or dense. This property of subgroups of the additive group ... More
On an arithmetic convolutionFeb 01 2014May 20 2014The Cauchy-type product of two arithmetic functions $f$ and $g$ on nonnegative integers is defined as $(f\bullet g)(k):=\sum_{m=0}^{k} {k\choose m}f(m)g(k-m)$. We explore some algebraic properties of the aforementioned convolution, which is a fundamental-characteristic ... More
Quantum effects in biology: master equation studies of exciton motion in photosynthetic systemsMar 01 2012The present review is devoted to our recent studies on the excitonic motion in photosynthetic systems. In photosynthesis, the light photon is absorbed to create an exciton in the antenna complex of the photosynthetic pigments. This exciton then migrates ... More
Controllable diffusion of cold atoms in a harmonically driven and tilted optical lattice: Decoherence by spontaneous emissionDec 11 2006May 07 2008We have studied some transport properties of cold atoms in an accelerated optical lattice in the presence of decohering effects due to spontaneous emission. One new feature added is the effect of an external AC drive. As a result we obtain a tunable diffusion ... More
Non-linear Nyquist theorem: A conjectureSep 23 2014Thermodynamics of equilibrium states is well established. However, in nonequilibrium few general results are known. One prime and important example is that of Nyquist theorem. It relates equilibrium tiny voltage fluctuations across a conductor with its ... More
Relaxation of Femtosecond Non-equilibrium Electrons in a Metallic SampleDec 11 2006A model calculation is given for the energy relaxation of a non-equilibrium distribution of hot electrons prepared in a metallic sample that has been subjected to homogeneous photo-excitation by a femtosecond laser pulse. The model assumes that the delta ... More
The Texture One Zero Neutrino Mass Matrix With Vanishing TraceMar 28 2018In the light of latest neutrino oscillation data, we have investigated the one zero Majorana neutrino mass matrix $M_{\nu}$ with zero sum condition of mass eigen values in the flavor basis, where charged lepton mass matrix is diagonal. Among the six possible ... More
Implication of rephasing invariant parameters on texture specific mass matricesApr 03 2018In the quark sector, Jarlskog rephasing invariant parameter $J_{CP}$ has important implications for the CP violation as well as phase structure of the quark mass matrices. In fact all CP violating effects in this sector are proportional to the magnitude ... More
Studying the physics potential of long-baseline experiments in terms of new sensitivity parametersAug 24 2016We investigate physics opportunities to constraint leptonic CP-violation phase $\delta_{CP}$ through numerical analysis of working neutrino oscillation probability parameters, in the context of long base line experiments. Numerical analysis of two parameters, ... More
Sixth-order schemes for laser--matter interaction in Schrödinger equationOct 12 2018Control of quantum systems via lasers has numerous applications that require fast and accurate numerical solution of the Schr\"odinger equation. In this paper we present three strategies for extending any sixth-order scheme for Schr\"odinger equation ... More
Orbit spaces of free involutions on the product of two projective spacesJan 04 2010Let $X$ be a finitistic space having the mod 2 cohomology algebra of the product of two projective spaces. We study free involutions on $X$ and determine the possible mod 2 cohomology algebra of orbit space of any free involution, using the Leray spectral ... More
Limiting behavior of a diffusion in an asymptotically stable environmentMay 16 2005Let $V$ be a two sided random walk and let $X$ denote a real valued diffusion process with generator ${1/2}e^{V([x])}\frac{d}{dx}(e^{-V([x])}\frac{d}{dx})$. This process is known to be the continuous equivalent of the one dimensional random walk in random ... More
Nonlocal Pertubations of Fractional Choquard EquationMay 16 2017We study the equation \begin{equation} (-\Delta)^{s}u+V(x)u= (I_{\alpha}*|u|^{p})|u|^{p-2}u+\lambda(I_{\beta}*|u|^{q})|u|^{q-2}u \quad\mbox{ in } \R^{N}, \end{equation} where $I_\gamma(x)=|x|^{-\gamma}$ for any $\gamma\in (0,N)$, $p, q >0$, $\alpha,\beta\in ... More
A Short Proof that Lebesgue Outer Measure of an Interval is its LengthNov 13 2018We prove the statement in the title using the connectedness of the interval in real line.
Students' conceptual knowledge of energy and momentumFeb 25 2016We investigate student understanding of energy and momentum concepts at the level of introductory physics by designing and administering a 25-item multiple choice test and conducting individual interviews. We find that most students have difficulty in ... More
Assessing Student Expertise in Introductory Physics with Isomorphic Problems, Part I: Performance on Non-intuitive Problem Pair from Introductory PhysicsFeb 21 2016Investigations related to expertise in problem solving and ability to transfer learning from one context to another are important for developing strategies to help students perform more expert-like tasks. Here we analyze written responses to a pair of ... More
Problem Solving and LearningFeb 20 2016One finding of cognitive research is that people do not automatically acquire usable knowledge by spending lots of time on task. Because students' knowledge hierarchy is more fragmented, "knowledge chunks" are smaller than those of experts. The limited ... More
Effectiveness of group interaction on conceptual standardized test performanceJul 25 2002Jul 26 2002We analyze the effectiveness of working in pairs on the Conceptual Survey of Electricity and Magnetism test in a calculus-based introductory physics course. The group performance shows large normalized gain and evidence for co-construction. We discuss ... More
Vertex-disjoint Cycle Cover for graph signal processingFeb 19 2016Eigenvectors of the Laplacian of a cycle graph exhibit the sinusoidal characteristics of the standard DFT basis, and signals defined on such graphs are amenable to linear shift invariant (LSI) operations. In this paper we propose to reduce a generic graph ... More
Interactive learning tutorials on quantum mechanicsMar 10 2016We discuss the development and evaluation of quantum interactive learning tutorials (QuILTs) which are suitable for undergraduate courses in quantum mechanics. QuILTs are based on the investigation of student difficulties in learning quantum physics. ... More
Student understanding of Symmetry and Gauss' lawFeb 24 2016Helping students learn why Gauss' law can or cannot be easily applied to determine the strength of the electric field at various points for a particular charge distribution, and then helping them learn to determine the shape of the Gaussian surfaces if ... More
Bohm's realist interpretation of Quantum mechanicsMay 13 2008A brief account of the world view of classical physics is given first. We then recapitulate as to why the Copenhagen interpretation of the quantum mechanics had to renounce most of the attractive features of the clasical world view such as a causal description, ... More
Hidden Variables, Non Contextuality and Einstein-Locality in Quantum MechanicsJul 19 2005Jul 25 2005We discuss the problem of hidden variables and the motivation for introducting them in quantum mechanics. These include determinism, and the problem of meassurement and incompleteness. We first discuss Von-Neumann's imposisbility proof and then analyse ... More
Numerical loop quantum cosmology: an overviewAug 27 2012A brief review of various numerical techniques used in loop quantum cosmology and results is presented. These include the way extensive numerical simulations shed insights on the resolution of classical singularities, resulting in the key prediction of ... More
Loop cosmological dynamics and dualities with Randall-Sundrum braneworldsMar 11 2006The discrete quantum geometric effects play an important role in dynamical evolution in the loop quantum cosmology. These effects which are significant at the high energies lead to the quadratic energy density modifications to the Friedmann equation, ... More
Time-Frequency analysis via the Fourier RepresentationApr 18 2016The nonstationary nature of signals and nonlinear systems require the time-frequency representation. In time-domain signal, frequency information is derived from the phase of the Gabor's analytic signal which is practically obtained by the inverse Fourier ... More
The Yang-Mills and chiral fields in six dimensionsNov 14 2012Feb 20 2013In previous work (Singh, 2011), we constructed an action in six dimensions using Yang-Mills fields and an auxiliary Abelian field. Here we first write down all the equations of motion and the constraints which arise from such an action. From these equations ... More
Super-Yang-Mills and M5-branesJul 18 2011Aug 23 2011We uplift 5-dimensional super-Yang-Mills theory to a 6-dimensional gauge theory with the help of a space-like constant vector $\eta^M$, whose norm determines the Yang-Mills coupling constant. After the localization of $\eta^M$ the 6D gauge theory acquires ... More
New Supersymmetric Vacua for N=4, D=4 Gauged SupergravityJan 08 1998May 26 1998In this paper we obtain supersymmetric brane-like configurations in the vacuum of N=4 gauged $SU(2)\times SU(2)$ supergravity theory in four spacetime dimensions. Almost all of these vacuum solutions preserve either half or one quarter of the supersymmetry ... More
Macroscopic String-like Solutions in Massive SupergravityOct 24 1997Nov 25 1997In this report we obtain explicit string-like solutions of equations of motion of massive heterotic supergravity recently obtained by Bergshoeff, Roo and Eyras. We also find consistent string source which can be embedded in these backgrounds when space-time ... More
SU(N) membrane $B\wedge F$ theory with dual-pairsNov 11 2008Dec 04 2008We construct a SU(N) membrane $B\wedge F$ theory with dual pairs of scalar and tensor fields. The moduli space of the theory is precisely that of $N$ M2-branes on the noncompact flat space. The theory possesses explicit SO(8) invariance and is an extension ... More