408 research outputs found

    Higher order two-mode and multi-mode entanglement in Raman processes

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    The existence of higher order entanglement in the stimulated and spontaneous Raman processes is established using the perturbative solutions of the Heisenberg equations of motion for various field modes that are obtained using the Sen-Mandal technique and a fully quantum mechanical Hamiltonian that describes the stimulated and spontaneous Raman processes. Specifically, the perturbative Sen-Mandal solutions are exploited here to show the signature of the higher order two-mode and multi-mode entanglement. In some special cases, we have also observed higher order entanglement in the partially spontaneous Raman processes. Further, it is shown that the depth of the nonclassicality indicators (parameters) can be manipulated by the specific choice of coupling constants, and it is observed that the depth of nonclassicality parameters increases with the order.Comment: 9 pages, 5 figures. arXiv admin note: text overlap with arXiv:1301.028

    Modified scaling in kk-essence model in interacting dark energy - dark matter scenario

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    It has been shown by \textit{Scherrer and Putter et.al} that, when dynamics of dark energy is driven by a homogeneous kk-essence scalar field ϕ\phi, with a Lagrangian of the form L=V0F(X)L = V_0F(X) with a constant potential V0V_0 and X=12μϕμϕ=12ϕ˙2X = \frac{1}{2}\nabla^\mu\phi \nabla_\mu\phi = \frac{1}{2}\dot{\phi}^2, one obtains a scaling relation X(dF/dX)2=Ca6X(dF/dX)^2 = Ca^{-6} , where CC is a constant and aa is the FRW scale factor of the universe. The separate energy conservation in the dark energy sector and the constancy of kk-essence potential are instrumental in obtaining such a scaling. In this paper, we have shown that even when considering time-dependent interactions between dark energy and dark matter, the constancy of kk-essence potential may lead to a modified form of scaling. We have obtained such a scaling relation for a particular class of parametrisation of the source term occurring in the continuity equation of dark energy and dark matter in the interacting scenario. We used inputs from the JLA analysis of luminosity distance and redshift data from Supernova Ia observations, to obtain the modified form of the scaling.Comment: 21 pages and 6 figures. This version has been accepted for publication in European Physical Journal Plu

    Indolicidin Targets Duplex DNA: Structural and Mechanistic Insight through a Combination of Spectroscopy and Microscopy

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    Indolicidin (IR13), a 13‐residue antimicrobial peptide from the cathelicidin family, is known to exhibit a broad spectrum of antimicrobial activity against various microorganisms. This peptide inhibits bacterial DNA synthesis resulting in cell filamentation. However, the precise mechanism remains unclear and requires further investigation. The central PWWP motif of IR13 provides a unique structural element that can wrap around, and thus stabilize, duplex B‐type DNA structures. Replacements of the central Trp‐Trp pair with Ala‐Ala, His‐His, or Phe‐Phe residues in the PxxP motif significantly affects the ability of the peptide to stabilize duplex DNA. Results of microscopy studies in conjunction with spectroscopic data confirm that the DNA duplex is stabilized by IR13, thereby inhibiting DNA replication and transcription. In this study we provide high‐resolution structural information on the interaction between indolicidin and DNA, which will be beneficial for the design of novel therapeutic antibiotics based on peptide scaffolds. That′s a wrap! The PWWP short peptide derived from indolicidin provides a unique structural element that stabilizes the DNA duplex. Substitution of Trp residues in PWWP with Ala, His, or Phe significantly destabilizes the DNA duplex structure, thereby establishing a strong correlation between the surface area of the residues (decreasing order: Ala<His≤Phe<Trp) present between the PxxP domain and DNA stabilization.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108345/1/cmdc_201402215_sm_miscellaneous_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/108345/2/2052_ftp.pd

    Investigating the accelerated expansion of the Universe through updated constraints on viable f(R)f(R) models within the metric formalism

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    Modified theories of gravity encompass a class of f(R)f(R)-models that seek to elucidate the observed late time accelerated expansion of the universe. In this study, we examine a set of viable f(R)f(R) models (Hu-Sawicki: two cases, Satrobinsky, Tsujikawa, exponential and arcTanh models) in metric formalism, using recent cosmological data sets: type Ia supernovae data, cosmic chronometer observations, baryonic acoustic oscillations data, data from H\textsc{ii} starburst galaxies, and local measurements of the Hubble parameter H0H_0. The model parameters are constrained using a Bayesian analysis with the Monte Carlo Markov Chain method. We employ statistical tools such as the Akaike Information Criterion, Bayesian Information Criterion, and reduced chi-square statistics to conduct a comparative investigation of these models. We determine the transition redshift, the evolution of total equation-of-state (EoS) parameter, and the EoS for the component responsible for current accelerated expansion to characterize the expansion's evolution. Taking into account the ``Hubble tension," we perform the study with and without a Gaussian prior for H0H_0 from local measurements. Our findings are as follows: (i) in many cases the f(R)f(R) models are strongly favored over the standard Λ\LambdaCDM model, (ii) the deviation parameter (bb) significantly deviates from zero in several cases, (iii) the inclusion of local H0H_0 not only increases the fitted value of H0H_0 (as expected) but also affects the gap between predictions of f(R)f(R) models and the Λ\LambdaCDM model, and (iv) the relevant quantities characterizing the (accelerated) expansion of the universe obtained in our models are consistent with those obtained in a model-independent way by others. Our investigation and results present a compelling case for pursuing further research on f(R)f(R) models with future observations to come

    A green process for chlorine-free benzaldehyde from the solvent-free oxidation of benzyl alcohol with molecular oxygen over a supported nano-size gold catalyst

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    Benzyl alcohol is oxidized selectively to benzaldehyde with high yield, with a little formation of benzylbenzoate, by molecular oxygen over a reusable nano-size gold catalyst supported on U3O8, MgO, Al2O3 or ZrO2 in the absence of any solvent

    Dark matter halo occupation: environment and clustering

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    We use a large dark matter simulation of a LambdaCDM model to investigate the clustering and environmental dependence of the number of substructures in a halo. Focusing on redshift z=1, we find that the halo occupation distribution is sensitive at the tens of percent level to the surrounding density and to a lesser extent to asymmetry of the surrounding density distribution. We compute the autocorrelation function of halos as a function of occupation, building on the finding of Wechsler et al. (2006) and Gao and White (2007) that halos (at fixed mass) with more substructure are more clustered. We compute the relative bias as a function of occupation number at fixed mass, finding a strong relationship. At fixed mass, halos in the top 5% of occupation can have an autocorrelation function ~ 1.5-2 times higher than the mean. We also compute the bias as a function of halo mass, for fixed halo occupation. We find that for group and cluster sized halos, when the number of subhalos is held fixed, there is a strong anticorrelation between bias and halo mass. Such a relationship represents an additional challenge to the halo model.Comment: 13 pages, 10 figures, MNRAS submitte
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