Results for "Bharat Ratra"

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Constraints on dark energy from the Lyα forest baryon acoustic oscillations measurement of the redshift 2.3 Hubble parameterDec 18 2012We use the Busca et al. (2012) measurement of the Hubble parameter at redshift z = 2.3 in conjunction with 21 lower z measurements, from Simon et al. (2005), Gaztanaga et al. (2009), Stern et al. (2010), and Moresco et al. (2012), to place constraints ... More
CMB Anisotropy in COBE-DMR-Normalized Flat $Λ$ CDM CosmogonyDec 23 1995We compute the cosmic microwave background (CMB) anisotropy in a low-density, flat, cosmological constant, cold dark matter model which is normalized to the two-year COBE DMR sky map. Although conclusions regarding model viability must remain tentative ... More
Hubble parameter data constraints on dark energyJun 21 2011Aug 20 2011We use Hubble parameter versus redshift data from Stern, et al(2010) and Gazta\~{n}aga, et al (2009) to place constraints on model parameters of constant and time-evolving dark energy cosmological models. These constraints are consistent with (through ... More
Non-Gaussian Error Distributions of LMC Distance Moduli MeasurementsJul 28 2015Dec 21 2015We construct error distributions for a compilation of 232 Large Magellanic Cloud (LMC) distance moduli values from de Grijs (2014) that give an LMC distance modulus of (m-M)_{0}=18.49 plus/minus 0.13 mag (median and 1 sigma symmetrized error). Central ... More
Hubble parameter measurement constraints on the cosmological deceleration-acceleration transition redshiftJan 22 2013We compile a list of 28 independent measurements of the Hubble parameter between redshifts 0.07 < z < 2.3 and use this to place constraints on model parameters of constant and time-evolving dark energy cosmologies. These H(z) measurements by themselves ... More
The Beginning and Evolution of the UniverseJun 11 2007Jul 08 2008We review the current standard model for the evolution of the Universe from an early inflationary epoch to the complex hierarchy of structure seen today. We summarize and provide key references for the following topics: observations of the expanding Universe; ... More
Using the tilted flat-$Λ$CDM and the non-flat $Λ$CDM inflation models to measure cosmological parameters from a compilation of observational dataDec 31 2017Jul 17 2018We use the physically-consistent tilted spatially-flat and non-flat $\Lambda\textrm{CDM}$ inflation models to constrain cosmological parameter values with the Planck 2015 cosmic microwave background (CMB) anisotropy data and recent Type Ia supernovae ... More
Cosmological-Model-Parameter Determination from Satellite-Acquired Type Ia and IIP Supernova DataAug 17 2000Jan 31 2001We examine the constraints that satellite-acquired Type Ia and IIP supernova apparent magnitude versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant $\Lambda$. High-quality ... More
Median Statistics Estimate of the Galactic Rotational VelocityMay 04 2018We compile a complete collection of 19 recent (since 2000) measurements of $\Theta_0$, the rotational velocity of the Milky Way at $R_0$ (the radial distance of the Sun from the Galactic center). These measurements use tracers that are believed to more ... More
The impact of a new median statistics $H_0$ prior on the evidence for dark radiationMay 30 2012Jul 26 2012Recent analyses that include cosmic microwave background (CMB) anisotropy measurements from the Atacama Cosmology Telescope and the South Pole Telescope have hinted at the presence of a dark radiation component at more than two standard deviations. However, ... More
Neutrino Mass Limit from Galaxy Cluster Number Density EvolutionMar 15 2005May 30 2005Measurements of the evolution with redshift of the number density of massive galaxy clusters are used to constrain the energy density of massive neutrinos and so the sum of neutrino masses $\sum m_\nu$. We consider a spatially-flat cosmological model ... More
Inflation and accelerated expansion TeVeS cosmological solutionsJan 07 2006Mar 19 2006We find exact exponentially expanding and contracting de Sitter solutions of the spatially homogeneous TeVeS cosmological equations of motion in the vacuum TeVeS model and a power law accelerated expanding solution in thepresence of an additional ideal ... More
Gaussian Processes, Median Statistics, Milky Way Rotation CurvesMar 03 2019Mar 05 2019We use the Iocco et al. (2015) compilation of 2,780 circular velocity measurements to analyze the Milky Way rotation curve. We find that the error bars for individual measurements are non-gaussian, and hence instead derive median statistics binned central ... More
First study of reionization in tilted flat and untilted non-flat dynamical dark energy inflation modelsJan 28 2019We examine the effects of dark energy dynamics and spatial curvature on cosmic reionization by studying reionization in tilted spatially-flat and untilted non-flat XCDM and $\phi$CDM dynamical dark energy inflation models that best fit the Planck 2015 ... More
Hubble parameter measurement constraints on the redshift of the deceleration-acceleration transition, dynamical dark energy, and space curvatureJul 12 2016We compile an updated list of 28 independent measurements of the Hubble parameter $H(z)$ between redshifts $0.1 \leq z \leq 2.36$ and use them to place constraints on model parameters of constant and time-varying dark energy cosmological models, both ... More
Time and distance constraints on accelerating cosmological modelsOct 05 2010Apr 08 2011The absence of guidance from fundamental physics about the mechanism behind cosmic acceleration has given rise to a number of alternative cosmological scenarios. These are based either on modifications of general relativistic gravitation theory on large ... More
Radio Galaxy Redshift-Angular Size Data Constraints on Dark EnergyJul 03 2002Oct 28 2002We use FRIIb radio galaxy redshift-angular size data to constrain cosmological parameters in a dark energy scalar field model. The derived constraints are consistent with but weaker than those determined using Type Ia supernova redshift-magnitude data. ... More
Large-scale structure in COBE-normalized cold dark matter cosmogoniesFeb 10 1997We study the clustering of the mass distribution in COBE-normalized open and flat CDM models using large N-body simulations. With an age of the universe of 14 Gyr (12 Gyr) for the flat (open) models and a baryon density fixed by nucleosynthesis constraints, ... More
CMB Anisotropy Constraints on Open and Flat-Lambda CDM Cosmogonies from UCSB South Pole, ARGO, MAX, White Dish, and SuZIE DataJan 04 1999We use combinations of ten small-scale cosmic microwave background anisotropy data sets from the UCSB South Pole 1994, ARGO, MAX 4 and 5, White Dish and SuZIE experiments to constrain cosmogonies. We consider open and spatially-flat-Lambda cold dark matter ... More
Galaxy cluster angular size data constraints on dark energyMay 27 2011Jul 20 2011We use angular size versus redshift data for galaxy clusters from Bonamente et al. (2006) to place constraints on model parameters of constant and time-evolving dark energy cosmological models. These constraints are compatible with those from other recent ... More
Median Statistics, H_0, and the Accelerating UniverseJun 07 2000Oct 25 2000(Abridged) We develop median statistics that provide powerful alternatives to chi-squared likelihood methods and require fewer assumptions about the data. Applying median statistics to Huchra's compilation of nearly all estimates of the Hubble constant, ... More
Median statistics cosmological parameter valuesNov 04 2013We present median statistics central values and ranges for 12 cosmological parameters, using 582 measurements (published during 1990-2010) collected by Croft & Dailey (2011). On comparing to the recent Planck collaboration Ade et al. 2013 estimates of ... More
CMB Anisotropy Constraints on Flat-Lambda and Open CDM Cosmogonies from DMR, UCSB South Pole, Python, ARGO, MAX, White Dish, OVRO, and SuZIE DataSep 26 2002We use joint likelihood analyses of combinations of fifteen cosmic microwave background (CMB) anisotropy data sets from the DMR, UCSB South Pole 1994, Python I--III, ARGO, MAX 4 and 5, White Dish, OVRO, and SuZIE experiments to constrain cosmogonies. ... More
Galactic Foreground Constraints from the Python V Cosmic Microwave Background Anisotropy DataJan 29 2003Apr 24 2003We constrain Galactic foreground contamination of the Python V cosmic microwave background anisotropy data by cross correlating it with foreground contaminant emission templates. To model foreground emission we use 100 and 12 $\mu$m dust emission templates ... More
Observational constraints on the tilted spatially-flat and the untilted nonflat $φ$CDM dynamical dark energy inflation modelsJul 17 2018Oct 10 2018We constrain spatially-flat tilted and nonflat untilted scalar field ($\phi$) dynamical dark energy inflation ($\phi$CDM) models by using Planck 2015 cosmic microwave background (CMB) anisotropy measurements and recent baryonic acoustic oscillation distance ... More
Observational constraints on the tilted flat-XCDM and the untilted nonflat XCDM dynamical dark energy inflation parameterizationsMar 14 2018Oct 13 2018We constrain tilted spatially-flat and untilted nonflat XCDM dynamical dark energy inflation parameterizations using Planck 2015 cosmic microwave background (CMB) anisotropy data and recent baryonic acoustic oscillations distance measurements, Type Ia ... More
Measuring the Hubble constant and spatial curvature from supernova apparent magnitude, baryon acoustic oscillation, and Hubble parameter dataSep 10 2018Cosmic microwave background (CMB) anisotropy (spatial inhomogeneity) data provide the tightest constraints on the Hubble constant, matter density, spatial curvature, and dark energy dynamics. Other data, sensitive to the evolution of only the spatially ... More
Observational constraints on the tilted flat-XCDM and the untilted nonflat XCDM dynamical dark energy inflation parameterizationsMar 14 2018Apr 17 2019We constrain tilted spatially-flat and untilted nonflat XCDM dynamical dark energy inflation parameterizations using Planck 2015 cosmic microwave background (CMB) anisotropy data and recent baryonic acoustic oscillations distance measurements, Type Ia ... More
Observational constraints on non-flat dynamical dark energy cosmological modelsAug 04 2013Jun 15 2014We constrain two non-flat time-evolving dark energy cosmological models by using Hubble parameter data, Type Ia supernova apparent magnitude measurements, and baryonic acoustic oscillation peak length scale observations. The inclusion of space curvature ... More
Determining the Hubble constant from Hubble parameter measurementsJun 23 2016We use 28 Hubble parameter measurements to determine the Hubble constant $H_0$ in four cosmological models. The $H_0$ values we measure are more consistent with the lower values determined from recent cosmic microwave background and baryon acoustic oscillation ... More
Constraints on dark energy dynamics and spatial curvature from Hubble parameter and baryon acoustic oscillation dataMay 16 2018Jun 24 2018We use all available baryon acoustic oscillation distance measurements and Hubble parameter data to constrain the cosmological constant $\Lambda$, dynamical dark energy, and spatial curvature in simple cosmological models. We find that the consensus spatially ... More
Baryon acoustic oscillation, Hubble parameter, and angular size measurement constraints on the Hubble constant, dark energy dynamics, and spatial curvatureFeb 08 2019In this paper we use all available baryon acoustic oscillation and Hubble parameter data to constrain six dark energy cosmological models, both spatially flat and non-flat. These data mildly favor (at 1.3-1.4$\sigma$) closed spatial hypersurfaces in the ... More
Effects of Foreground Contamination on the Cosmic Microwave Background Anisotropy Measured by MAPJun 30 2001Nov 24 2001We study the effects of diffuse Galactic, far-infrared extragalactic source, and radio point source emission on the cosmic microwave background (CMB) anisotropy data anticipated from the MAP experiment. We focus on the correlation function and genus statistics ... More
Forecasting cosmological parameter constraints from near-future space-based galaxy surveysJun 14 2012Oct 11 2012The next generation of space-based galaxy surveys are expected to measure the growth rate of structure to about a percent level over a range of redshifts. The rate of growth of structure as a function of redshift depends on the behaviour of dark energy ... More
Hubble parameter measurement constraints on dark energyNov 18 2012Jan 20 2013We use 21 Hubble parameter versus redshift data points, from Gazta\~{n}aga et al. (2009), Stern et al. (2010), and Moresco et al. (2012), to place constraints on model parameters of constant and time-evolving dark energy cosmologies. This is the largest ... More
Tentative Appraisal of Compatibility of Small-Scale CMB Anisotropy Detections in the Context of COBE-DMR-Normalized Open and Flat $Λ$ CDM CosmogoniesDec 29 1995Goodness-of-fit statistics are used to quantitatively establish the compatibility of CMB anisotropy predictions in a wide range of DMR-normalized, open and spatially-flat $\Lambda$, CDM cosmogonies with the set of all presently available small-scale CMB ... More
Non-Gaussian Error Distribution of $\rm{^{7}Li}$ Abundance MeasurementsSep 25 2014May 26 2015We construct the error distribution of $\rm{^{7}Li}$ abundance measurements for 66 observations (with error bars) used by Spite12 that give $\rm{A(Li)}=2.21 \pm 0.065$ (median and 1$\sigma$ symmetrized error). This error distribution is somewhat non-Gaussian, ... More
Hubble Parameter and Baryon Acoustic Oscillation Measurement Constraints on the Hubble Constant, the Deviation from the Spatially-Flat $Λ$cdm Model, The Deceleration-Acceleration Transition Redshift, and Spatial CurvatureNov 09 2017Mar 11 2018We compile a complete collection of reliable Hubble parameter $H(z)$ data to redshift $z \leq 2.36$ and use them with the Gaussian Process method to determine continuous $H(z)$ functions for various data subsets. From these continuous $H(z)$'s, summarizing ... More
Supernova Ia and Galaxy Cluster Gas Mass Fraction Constraints on Dark EnergyFeb 14 2006We use the Riess et al.(2004) supernova Ia apparent magnitude versus redshift data and the Allen et al.(2004) galaxy cluster gas mass fraction versus redshift data to constrain dark energy models. These data provide complementary constraints that when ... More
First study of reionization in the Planck 2015 normalized closed $Λ$CDM inflation modelNov 30 2017Jul 10 2018We study reionization in two non-flat $\Lambda$CDM inflation models that best fit the Planck 2015 cosmic microwave background anisotropy observations, ignoring or in conjunction with baryon acoustic oscillation distance measurements. We implement a principal ... More
Dark matter deficient galaxies in the Illustris flat-$Λ$CDM model structure formation simulationSep 16 2018Surveying dark matter deficient galaxies (those with dark matter mass to stellar mass ratio $M_{\rm dm}/M_{\rm star}<1$) in the Illustris simulation of structure formation in the flat-$\Lambda$CDM cosmogony, we find $M_{\rm star} \approx 2 \times 10^8\, ... More
Binned Hubble parameter measurements and the cosmological deceleration-acceleration transitionMay 08 2013Weighted mean and median statistics techniques are used to combine 23 independent lower redshift, $z<1.04$, Hubble parameter, $H(z)$, measurements and determine binned forms of $H(z)$. When these are combined with 5 higher redshift, $1.3\leqslant z \leqslant ... More
CMB Temperature Anisotropy from Broken Spatial Isotropy due to an Homogeneous Cosmological Magnetic FieldJul 26 2008Sep 09 2008We derive the cosmic microwave background temperature anisotropy two-point correlation function (including off-diagonal correlations) from broken spatial isotropy due to an arbitrarily oriented homogeneous cosmological magnetic field.
Cosmological constraints from large-scale structure growth rate measurementsDec 18 2013Jun 22 2014We compile a list of $14$ independent measurements of large-scale structure growth rate between redshifts $0.067 \leq z \leq 0.8$ and use this to place constraints on model parameters of constant and time-evolving general-relativistic dark energy cosmologies. ... More
Determining the Hubble constant from Hubble parameter measurementsJun 23 2016Dec 15 2016We use 28 Hubble parameter, $H(z)$, measurements at intermediate redshifts $0.07 \leq z \leq 2.3$ to determine the present-day Hubble constant $H_0$ in four cosmological models. We measure $H_0 = 68.3^{ +2.7}_{ -2.6 }, 68.4^{ +2.9 }_{ -3.3 }, 65.0^{ +6.5 ... More
Cosmographic bounds on the cosmological deceleration-acceleration transition redshift in $f(\mathcal{R})$ gravityMar 06 2014We examine the observational viability of a class of $f(\mathcal{R})$ gravity cosmological models. Particular attention is devoted to constraints from the recent observational determination of the redshift of the cosmological deceleration-acceleration ... More
UCSB South Pole 1994 CMB anisotropy measurement constraints on open and flat-Lambda CDM cosmogoniesFeb 27 1996Feb 11 1997We develop methods to account for experimental and observational uncertainties in likelihood analyses of data from cosmic microwave background (CMB) anisotropy experiments and apply them to an analysis of the UCSB South Pole 1994 (SP94) experiment. Observationally ... More
Numerical simulations of the decay of primordial magnetic turbulenceApr 19 2010May 13 2010We perform direct numerical simulations of forced and freely decaying 3D magnetohydrodynamic turbulence in order to model magnetic field evolution during cosmological phase transitions in the early Universe. Our approach assumes the existence of a magnetic ... More
Median Statistics Analysis of Deuterium Abundance Measurements and Spatial Curvature ConstraintsAug 04 2018Zavarygin et al. (2018) compiled a list of 15 deuterium abundance measurements, discarded two because the remaining 13 measurements are then consistent with gaussianity, and found that the weighted mean baryon density (Omega_b h^2) determined from the ... More
Looking for Cosmological Alfven Waves in WMAP DataMar 30 2004Apr 27 2004A primordial cosmological magnetic field induces and supports vorticity or Alfven waves, which in turn generate cosmic microwave background (CMB) anisotropies. A homogeneous primordial magnetic field with fixed direction induces correlations between the ... More
CBR Anisotropy in an Open Inflation, CDM CosmogonyJun 27 1994We compute the cosmic background radiation anisotropy, produced by energy-density fluctuations generated during an early epoch of inflation, in an open cosmological model based on the cold dark matter scenario. At $\Omega_0 \sim$ 0.3 -- 0.4, the COBE ... More
Nonflat time-variable dark energy cosmologyJul 28 2013Dec 19 2013We generalize the time-variable dark energy scalar field $\Phi$ model ($\Phi$CDM) to nonflat space. We show that even in the space-curvature-dominated epoch the scalar field solution is a time-dependent fixed point or attractor, with scalar field energy ... More
Gaussianity of Degree-Scale Cosmic Microwave Background Anisotropy ObservationsFeb 23 2001Feb 24 2001We present results from a first test of the Gaussianity of degree-scale cosmic microwave background (CMB) anisotropy. We investigate Gaussianity of the CMB anisotropy by studying the topology of CMB anisotropy maps from the QMAP and Saskatoon experiments. ... More
Cosmological magnetic braking and the formation of high-redshift, super-massive black holesJan 05 2019We study the effect of magnetic braking due to a primordial magnetic field in the context of the formation of massive ($\gtrsim 10^{4} M_\odot$) direct collapse black holes (DCBHs) at high redshifts. Under the assumption of axial symmetry, we analytically ... More
Constraints on dark energy from the lookback time versus redshift testJun 15 2009Aug 06 2010We use lookback time versus redshift data from galaxy clusters (Capozziello et al., 2004) and passively evolving galaxies (Simon et al., 2005), and apply a bayesian prior on the total age of the Universe based on WMAP measurements, to constrain dark energy ... More
COBE-DMR-normalised Open Inflation, CDM CosmogonyFeb 06 1995Fourier analysis on a cut sky of the two-year COBE DMR 53 and 90 GHz sky maps (in galactic coordinates) is used to determine the normalisation of an open inflation model based on the cold dark matter scenario. The normalised model is compared to measures ... More
Constraints on Scalar-Field Dark Energy from the Cosmic Lens All-Sky Survey Gravitational Lens StatisticsMar 10 2004Apr 16 2004We use the statistics of strong gravitational lensing based on the Cosmic Lens All-Sky Survey (CLASS) data to constrain cosmological parameters in a spatially-flat, inverse power-law potential energy density, scalar-field dark energy cosmological model. ... More
Faraday Rotation of the Cosmic Microwave Background Polarization by a Stochastic Magnetic FieldSep 30 2004Mar 24 2005A primordial cosmological magnetic field induces Faraday rotation of the cosmic microwave background polarization. This rotation produces a curl-type polarization component even when the unrotated polarization possesses only gradient-type polarization, ... More
CMB Anisotropy in COBE-DMR-Normalized Open CDM CosmogonyDec 22 1995We compute the CMB anisotropy in an open inflation CDM model which is normalized to the two-year DMR sky map. Presently available CMB data is consistent with $\Omega_0 \sim 0.3 - 0.4$, but does not strongly disfavour either $\Omega_0 \sim 0.1$ or $\Omega_0 ... More
Hubble parameter measurement constraints on the redshift of the deceleration-acceleration transition, dynamical dark energy, and space curvatureJul 12 2016Nov 15 2016We compile an updated list of 38 measurements of the Hubble parameter $H(z)$ between redshifts $0.07 \leq z \leq 2.36$ and use them to place constraints on model parameters of constant and time-varying dark energy cosmological models, both spatially flat ... More
Median Statistics Estimate of the Distance to the Galactic CenterAug 03 2017Nov 16 2017We show that error distributions of a compilation of 28 recent independent measurements of the distance from the Sun to the Galactic center, $R_{0}$, are wider than a standard Gaussian and best fit by an $n=4$ Student's $t$ probability density function. ... More
Implications of nuclear interaction for nuclear structure and astrophysics within the relativistic mean-field modelDec 08 2018In this dissertation, we have studied the implications of nuclear interaction for nuclear structure and astrophysics within the relativistic mean-field (RMF) model.
Shape co-existence and parity doublet in Zr isotopesSep 15 2014Dec 05 2014We studied the ground and excited states properties for Zr isotopes starting^M from proton to neutron drip-lines using the relativistic and non-relativistic mean field formalisms with BCS and Bogolyubov pairing. The celebrity NL3 and SLy4 parameter sets ... More
Constraints on non-flat cosmologies with massive neutrinos after Planck 2015Mar 23 2016Jul 19 2016We investigate two dark energy cosmological models (i.e., the $\Lambda$CDM and $\phi$CDM models) with massive neutrinos assuming two different neutrino mass hierarchies in both the spatially flat and non-flat scenarios, where in the $\phi$CDM model the ... More
Evolution of inflation-generated magnetic field through phase transitionsJun 12 2012Oct 11 2012We study the evolution of an inflation-generated magnetic field, due to its coupling to fluid motions, during cosmological phase transitions. We find that the magnetic field stays almost unchanged on large scales, while on small scales the spectrum is ... More
Galactic Foregrounds in OVRO and UCSB South Pole 1994 Cosmic Microwave Background Anisotropy DataOct 19 2001Jul 04 2002We study Galactic emission foreground contamination of the OVRO and UCSB South Pole 1994 cosmic microwave background (CMB) anisotropy data by cross-correlating with templates of infrared dust emission and new high resolution $H_{\alpha}$ data. $H_{\alpha}$ ... More
Primordial magnetic field limits from cosmological dataSep 10 2010We study limits on a primordial magnetic field arising from cosmological data, including that from big bang nucleosynthesis, cosmic microwave background polarization plane Faraday rotation limits, and large-scale structure formation. We show that the ... More
Python I, II, and III CMB Anisotropy Measurement Constraints on Open and Flat-Lambda CDM CosmogoniesMay 11 1999We use Python I, II, and III cosmic microwave background anisotropy data to constrain cosmogonies. We account for the Python beamwidth and calibration uncertainties. We consider open and spatially-flat-Lambda cold dark matter cosmogonies, with nonrelativistic-mass ... More
Galaxy cluster number count data constraints on cosmological parametersOct 11 2011Oct 31 2012[Abridged] We use data on massive galaxy clusters ($M_{\rm cluster} > 8 \times 10^{14} h^{-1} M_\odot$ within a comoving radius of $R_{\rm cluster} = 1.5 h^{-1}\Mpc$) in the redshift range $0.05 \lesssim z \lesssim 0.83$ to place constraints, simultaneously, ... More
Binned Cosmic Microwave Background Anisotropy Power Spectra: Peak LocationFeb 15 2001We use weighted mean and median statistics techniques to combine individual cosmic microwave background (CMB) anisotropy detections and determine binned, multipole-space, CMB anisotropy power spectra. The resultant power spectra are peaked. The derived ... More
ARGO CMB Anisotropy Measurement Constraints on Open and Flat-Lambda CDM CosmogoniesJul 29 1998We use data from the ARGO cosmic microwave background (CMB) anisotropy experiment to constrain cosmogonies. We account for the ARGO beamwidth and calibration uncertainties, and marginalize over the offset removed from the data. Our derived amplitudes ... More
MAX 4 and MAX 5 CMB anisotropy measurement constraints on open and flat-Lambda CDM cosmogoniesAug 22 1997We account for experimental and observational uncertainties in likelihood analyses of cosmic microwave background (CMB) anisotropy data from the MAX 4 and MAX 5 experiments. These analyses use CMB anisotropy spectra predicted in open and spatially-flat ... More
OVRO CMB Anisotropy Measurement Constraints on Flat-Lambda and Open CDM CosmogoniesAug 10 2002We use Owens Valley Radio Observatory (OVRO) cosmic microwave background (CMB) anisotropy data to constrain cosmological parameters. We account for the OVRO beamwidth and calibration uncertainties, as well as the uncertainty induced by the removal of ... More
COBE-DMR-Normalized Dark Energy CosmogonyJun 06 2003Aug 19 2003Likelihood analyses of the COBE-DMR sky maps are used to determine the normalization of the inverse-power-law-potential scalar field dark energy model. Predictions of the DMR-normalized model are compared to various observations to constrain the allowed ... More
CMB Anisotropy Correlation Function and Topology from Simulated Maps for MAPNov 06 1997We have simulated cosmic microwave background (CMB) anisotropy maps for several COBE-DMR-normalized cold dark matter (CDM) cosmogonies, to make predictions for the upcoming MAP experiment. We have studied the sensitivity of the simulated MAP data to cosmology, ... More
Inferring neutron star properties from GW170817 with universal relationsFeb 12 2019Feb 22 2019Because all neutron stars share a common equation of state, tidal deformability constraints from the compact binary coalescence GW170817 have implications for the properties of neutron stars in other systems. Using equation-of-state insensitive relations ... More
A H-K Clustering Algorithm For High Dimensional Data Using Ensemble LearningJan 11 2015Advances made to the traditional clustering algorithms solves the various problems such as curse of dimensionality and sparsity of data for multiple attributes. The traditional H-K clustering algorithm can solve the randomness and apriority of the initial ... More
Inferring neutron star properties from GW170817 with universal relationsFeb 12 2019Mar 04 2019Because all neutron stars share a common equation of state, tidal deformability constraints from the compact binary coalescence GW170817 have implications for the properties of neutron stars in other systems. Using equation-of-state insensitive relations ... More
Closed ideals and Lie ideals of $C_0(X) \otimes^{\min} A$Apr 01 2019In this article, we prove that a closed ideal of $C_0(X) \otimes^{\min} A$ is a finite sum of product ideals, where $X$ is a locally compact Hausdorff space and $A$ is $C^*$-algebra with only finitely many closed ideals. As an application, we characterize ... More
Inferring Neutron Star Properties from GW170817 with Universal RelationsFeb 12 2019Because all neutron stars share a common equation of state, tidal deformability constraints from the compact binary coalescence GW170817 have implications for the properties of neutron stars in other systems. Using equation-of-state insensitive relations ... More
Constraints on the moment of inertia of PSR J0737-3039A from GW170817Jul 12 2018Mar 12 2019Continued observation of PSR J0737-3039, the double pulsar, is expected to yield a precise determination of its primary component's moment of inertia in the next few years. Since the moment of inertia depends sensitively on the neutron star's internal ... More
Inferring neutron star properties from GW170817 with universal relationsFeb 12 2019Mar 12 2019Because all neutron stars share a common equation of state, tidal deformability constraints from the compact binary coalescence GW170817 have implications for the properties of neutron stars in other systems. Using equation-of-state insensitive relations ... More
Role of isospin physics in supernova matter and neutron starsOct 28 2010We investigate the liquid-gas phase transition of hot protoneutron stars shortly after their birth following supernova explosion and the composition and structure of hyperon-rich (proto)neutron stars within a relativistic mean-field model where the nuclear ... More
Delayed Yielding in Creep, Time - Stress Superposition and Effective Time Theory for a Soft GlassMar 26 2012In this work we investigate creep flow of aqueous suspension of Laponite, a model soft glassy material, at different aging times and stresses. We observe that this system shows time - aging time - stress superposition over a range of aging times and stresses ... More
Dimensionality Reduction of Affine Variational Inequalities Using Random ProjectionsAug 20 2014Nov 08 2014We present a method for dimensionality reduction of an affine variational inequality (AVI) defined over a compact feasible region. Centered around the Johnson Lindenstrauss lemma, our method is a randomized algorithm that produces with high probability ... More
A Chandra Observation of a TW Hydrae Association Brown DwarfMay 07 2004We present Chandra observations of the young brown dwarf 2MASSW J1207334-393254, which is a probable member of the TW Hya association. Although this substellar object has strong H alpha emission, it has no detected X Ray flux in a fifty kilosecond ACIS-S ... More
Nuclear symmetry energy effects on liquid-gas phase transition in hot asymmetric nuclear matterJan 14 2010The liquid-gas phase transition in hot asymmetric nuclear matter is investigated within relativistic mean-field model using the density dependence of nuclear symmetry energy constrained from the measured neutron skin thickness of finite nuclei. We find ... More
Using SuZIE arcminute-scale CMB anisotropy data to probe open and flat-ΛCDM cosmogoniesFeb 21 1997We use arcminute-scale data from the Sunyaev-Zel'dovich Infrared Experiment to set limits on anisotropies in the cosmic microwave background radiation in open and spatially-flat-Lambda cold dark matter cosmogonies. There are no 2-sigma detections for ... More
A Computational Framework for Boundary Representation of Solid SweepsApr 01 2014This paper proposes a robust algorithmic and computational framework to address the problem of modeling the volume obtained by sweeping a solid along a trajectory of rigid motions. The boundary representation (simply brep) of the input solid naturally ... More
Generalizations of the Los-Tarski Preservation TheoremFeb 18 2013Jun 17 2013We present new preservation theorems that semantically characterize the $\exists^k \forall^*$ and $\forall^k \exists^*$ prefix classes of first order logic, for each natural number $k$. Unlike preservation theorems in the literature that characterize ... More
Quark-hadron phase transition in a chameleon Brans-Dicke model of brane gravityJan 01 2012Jan 20 2014In this work, the quark-hadron phase transition in a chameleon Brans-Dicke model of brane world cosmology within an effective model of QCD is investigated. Whereas, in the chameleon Brans-Dicke model of brane world cosmology, the Friedmann equation and ... More
Role of water in the enzymatic catalysis: study of ATP + AMP -> 2ADP conversion by adenylate kinaseDec 21 2010The catalytic conversion ATP + AMP -> 2ADP by the enzyme adenylate kinase (ADK) involves the binding of one ATP molecule to the LID domain and one AMP molecule to the NMP domain. The latter is followed by a phosphate transfer, and then the release of ... More
Emotion Detection and Analysis on Social MediaJan 24 2019In this paper, we address the problem of detection, classification and quantification of emotions of text in any form. We consider English text collected from social media like Twitter, which can provide information having utility in a variety of ways, ... More
HD 77361: A new case of super Li-rich K giant with anomalous low 12C/13C ratioAug 19 2009Results from high resolution spectroscopic analysis of HD 77361 are reported. The LTE analysis shows that HD 77361 is a K giant of atmospheric parameters: Teff = 4580 +/- 75 K, log$g$ = 2.5 +/- 0.1, and \xi_{t} = 1.40 +/-0.5 km/s. We found that the atmosphere ... More
Distance based (DBCP) Cluster Protocol for Heterogeneous Wireless Sensor NetworkSep 02 2014Clustering is an important concept to reduce the energy consumption and prolonging the life of a wireless sensor network. In heterogeneous wireless sensor network some of the nodes are equipped with more energy than the other nodes. Many routing algorithms ... More
Evacuation time estimate for a total pedestrian evacuation using queuing network model and volunteered geographic informationOct 08 2015Estimating city evacuation time is a non-trivial problem due to the interaction between thousands of individual agents, giving rise to various collective phenomena, such as bottleneck formation, intermittent flow and stop-and-go waves. We present a mean ... More
Deep Model Compression: Distilling Knowledge from Noisy TeachersOct 30 2016Nov 02 2016The remarkable successes of deep learning models across various applications have resulted in the design of deeper networks that can solve complex problems. However, the increasing depth of such models also results in a higher storage and runtime complexity, ... More
A procedural framework and mathematical analysis for solid sweepsApr 04 2012Sweeping is a powerful and versatile method of designing objects. Boundary of volumes (henceforth envelope) obtained by sweeping solids have been extensively investigated in the past, though, obtaining an accurate parametrization of the envelope remained ... More
Energy Efficient (EECP) Clustered Protocol for Heterogeneous Wireless Sensor NetworkAug 14 2014Energy Conservation and prolonging the life of Wireless Sensor Network is one of the major issues in the wireless sensor network as sensor nodes are highly energy constrained devices. Many routing protocols have been proposed for sensor network, especially ... More
Energy Aware Clustering Protocol(EACP) For Heterogeneous WSNsAug 13 2014Energy saving to prolong the network life is an important design issue while developing a new routing protocol for wireless sensor network. Clustering is a key technique for this and helps in maximizing the network lifetime and scalability. Most of the ... More