11,035 research outputs found

    Properties of spectrally-defined red QSOs at z = 0.3-1.2

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    We investigated the properties of a sample of red Quasi-stellar Objects (QSOs) using optical, radio, and infrared data. These QSOs were selected from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) quasar catalog. We only selected sources with sky coverage of the Very Large Array Faint Images of the Radio Sky at Twenty-centimeters (VLA FIRST) survey, and searched for sources with Wide-field Infrared Survey Explorer (WISE) counterparts. We defined the spectral color of the QSOs based on the flux ratio of the rest frame 4000A˚\AA to 3000A˚\AA continuum emission to select red QSOs and typical QSOs. In accordance with this criterion, only QSOs with redshifts between 0.3 and 1.2 could be selected. We found that the red QSOs have stronger infrared emission than the typical QSOs do. We noted that the number ratios of the red QSOs to the typical QSOs decrease with increasing redshifts, although the number of the typical QSOs increase with redshifts. Furthermore, at high redshifts, the luminosity distributions of the typical QSOs and the red QSOs seem to have similar luminosity distribution peaks; however, at low redshifts, the luminosities of the red QSOs seem to be lower than those of the typical QSOs. These findings suggest that there might be at least two types of red QSOs in our QSO samples.Comment: 12 pages, 11 figures, 9 tables, ApJ accepte

    An Updated Analysis of Inert Higgs Doublet Model in light of the Recent Results from LUX, PLANCK, AMS-02 and LHC

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    In light of the recent discovery by the ATLAS and CMS experiments at the Large Hadron Collider (LHC) of a Higgs-like particle with a narrow mass range of 125-126 GeV, we perform an updated analysis on one of the popular scalar dark matter models, the Inert Higgs Doublet Model (IHDM). We take into account in our likelihood analysis of various experimental constraints, including recent relic density measurement, dark matter direct and indirect detection constraints as well as the latest collider constraints on the invisible decay width of the Higgs boson and monojet search at the LHC. It is shown that if the invisible decay of the standard model Higgs boson is open, LHC as well as direct detection experiments like LUX and XENON100 could put stringent limits on the Higgs boson couplings to dark matter. We find that the most favoured parameter space for IHDM corresponds to dark matter with a mass less than 100 GeV or so. In particular, the best-fit points are at the dark matter mass around 70 GeV where the invisible Higgs decay to dark matter is closed. Scalar dark matter in the higher mass range of 0.5-4 TeV is also explored in our study. Projected sensitivities for the future experiments of monojet at LHC-14, XENON1T and AMS-02 one year antiproton flux are shown to put further constraints on the existing parameter space of IHDM.Comment: Matches JCAP accepted version, 49 pages, 27 figure

    Annealed MAP

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    Maximum a Posteriori assignment (MAP) is the problem of finding the most probable instantiation of a set of variables given the partial evidence on the other variables in a Bayesian network. MAP has been shown to be a NP-hard problem [22], even for constrained networks, such as polytrees [18]. Hence, previous approaches often fail to yield any results for MAP problems in large complex Bayesian networks. To address this problem, we propose AnnealedMAP algorithm, a simulated annealing-based MAP algorithm. The AnnealedMAP algorithm simulates a non-homogeneous Markov chain whose invariant function is a probability density that concentrates itself on the modes of the target density. We tested this algorithm on several real Bayesian networks. The results show that, while maintaining good quality of the MAP solutions, the AnnealedMAP algorithm is also able to solve many problems that are beyond the reach of previous approaches.Comment: Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004

    A generic method to constrain the dark matter model parameters from Fermi observations of dwarf spheroids

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    Observation of gamma-rays from dwarf galaxies is an effective way to search for particle dark matter. Using 4-year data of Fermi-LAT observations on a series of Milky Way satellites, we develop a general way to search for the signals from dark matter annihilation in such objects. Instead of giving prior information about the energy spectrum of dark matter annihilation, we bin the Fermi-LAT data into several energy bins and build a likelihood map in the "energy bin - flux" plane. The final likelihood of any spectrum can be easily derived through combining the likelihood of all the energy bins. It gives consistent result with that directly calculated using the Fermi Scientific Tool. This method is very efficient for the study of any specific dark matter models with gamma-rays. We use the new likelihood map with Fermi-LAT 4 year data to fit the parameter space in three representative dark matter models: i) toy dark matter model, ii) effective dark matter operators, and iii) supersymmetric neutralino dark matter.Comment: Matches JCAP accepted version, 8 pages, 6 figure

    LikeDM: likelihood calculator of dark matter detection

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    With the large progress in searches for dark matter (DM) particles with indirect and direct methods, we develop a numerical tool that enables fast calculations of the likelihoods of specified DM particle models given a number of observational data, such as charged cosmic rays from space-borne experiments (e.g., PAMELA, AMS-02), gamma-rays from the Fermi space telescope, and underground direct detection experiments. The purpose of this tool --- LikeDM, likelihood calculator for dark matter detection --- is to bridge the gap between a particle model of DM and the observational data. The intermediate steps between these two, including the astrophysical backgrounds, the propagation of charged particles, the analysis of Fermi gamma-ray data, as well as the DM velocity distribution and the nuclear form factor, have been dealt with in the code. We release the first version (v1.0) focusing on the constraints from indirect detection of DM with charged cosmic and gamma rays. Direct detection will be implemented in the next version. This manual describes the framework, usage, and related physics of the code. The code LikeDM can be download from https://likedm.hepforge.org/Comment: v2, published in Computer Physics Communications, "LikeDM can be download from https://likedm.hepforge.org/

    Block Shelves for Visual Programming Languages

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    The blocks editor, such as the editor in Scratch, is widely applied for visual programming languages (VPL) nowadays. Despite it's friendly for non-programmers, it exists three main limitations while displaying block codes: (1) the readability, (2) the program structure, and (3) the re-use. To cope with these issues, we introduce a novel formatting tool, block shelves, into the editor for organizing blocks. A user could utilize shelves to constitute a user-defined structure for the VPL projects. Based on the experiment results, block shelves improves the block code navigating and searching significantly. Besides, for achieving code re-use, users could use shelf export/import to share/re-use their block codes between projects in the file format of eXtensible Markup Language (xml.) All functions were demonstrated on MIT App inventor 2, while all modifications were made in Google Blockly.Comment: 6 pages, 6 figures, short pape

    The sorting index on colored permutations and even-signed permutations

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    We define a new statistic sor\mathsf{sor} on the set of colored permutations Gr,n\mathsf{G}_{r,n} and prove that it has the same distribution as the length function. For the set of restricted colored permutations corresponding to the arrangements of nn non-attacking rooks on a fixed Ferrers shape we show that the following two sequences of set-valued statistics are joint equidistributed: (β„“,Rmil0,Rmil1,...,Rmilrβˆ’1(\ell,\mathsf{Rmil}^0,\mathsf{Rmil}^1,...,\mathsf{Rmil}^{r-1}, Lmil0,Lmil1,...,Lmilrβˆ’1\mathsf{Lmil}^0,\mathsf{Lmil}^1,...,\mathsf{Lmil}^{r-1}, Lmal0,Lmal1,...,Lmalrβˆ’1\mathsf{Lmal}^0,\mathsf{Lmal}^1,...,\mathsf{Lmal}^{r-1}, Lmap0,Lmap1,...,Lmaprβˆ’1)\mathsf{Lmap}^0,\mathsf{Lmap}^1,...,\mathsf{Lmap}^{r-1}) and (sor,Cyc0,Cycrβˆ’1,...,Cyc1(\mathsf{sor},\mathsf{Cyc}^0,\mathsf{Cyc}^{r-1},...,\mathsf{Cyc}^{1}, Lmic0,Lmicrβˆ’1,...,Lmic1\mathsf{Lmic}^0,\mathsf{Lmic}^{r-1},...,\mathsf{Lmic}^{1}, Lmal0,Lmal1,...,Lmalrβˆ’1\mathsf{Lmal}^0,\mathsf{Lmal}^1,...,\mathsf{Lmal}^{r-1}, Lmap0,Lmap1,...,Lmaprβˆ’1)\mathsf{Lmap}^0,\mathsf{Lmap}^1,...,\mathsf{Lmap}^{r-1}). Analogous results are also obtained for Coxeter group of type DD. Our results extend recent results of Petersen, Chen-Gong-Guo and Poznanovi\'{c}.Comment: 28 pages, 2 figures. Some typos are corrected in this versio

    Set-valued sorting index and joint equidistributions

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    Recently Petersen defined a new Mahonian index sor over the symmetric group Sn\mathfrak{S}_n and proved that (inv,rlmin)(\text{inv}, \text{rlmin}) and (sor,cyc)(\text{sor}, \text{cyc}) have the same joint distribution. Foata and Han proved that the pairs of set-valued statistics (Cyc,Rmil),(Cyc,Lmap),(Rmil,Lmap)(\text{Cyc}, \text{Rmil}), (\text{Cyc}, \text{Lmap}), (\text{Rmil}, \text{Lmap}) have the same joint distribution over Sn\mathfrak{S}_n. In this paper we introduce the set-valued statistics Inv,Lmil,Sor\text{Inv}, \text{Lmil}, \text{Sor} and Lmicycl1\text{Lmicycl}_1 and generalize simultaneously results of Petersen and Foata-Han and find many equidistributed triples of set-valued statistics and quadruples of statistics.Comment: 12 pages, 1 figur

    Toric gg-polynomials of hook shape lattice Path Matroid Polytopes and product of simplices

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    It is known that a lattice path matroid polytope can be associated with two given noncrossing lattice paths on ZΓ—Z\mathbb{Z}\times\mathbb{Z} with the same end points. In this short note we give explicit formulae for the ff-vector, toric ff- and gg-polynomials of a lattice path matroid polytope when two boundary paths enclose a hook shape.Comment: 15 pages, 3 figure

    G2HDM : Gauged Two Higgs Doublet Model

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    A novel model embedding the two Higgs doublets in the popular two Higgs doublet models into a doublet of a non-abelian gauge group SU(2)HSU(2)_H is presented. The Standard Model SU(2)LSU(2)_L right-handed fermion singlets are paired up with new heavy fermions to form SU(2)HSU(2)_H doublets, while SU(2)LSU(2)_L left-handed fermion doublets are singlets under SU(2)HSU(2)_H. Distinctive features of this anomaly-free model are: (1) Electroweak symmetry breaking is induced from spontaneous symmetry breaking of SU(2)HSU(2)_H via its triplet vacuum expectation value; (2) One of the Higgs doublet can be inert, with its neutral component being a dark matter candidate as protected by the SU(2)HSU(2)_H gauge symmetry instead of a discrete Z2Z_2 symmetry in the usual case; (3) Unlike Left-Right Symmetric Models, the complex gauge fields (W1β€²βˆ“iW2β€²)(W_1^{\prime}\mp i W_2^{\prime}) (along with other complex scalar fields) associated with the SU(2)HSU(2)_H do {\it not} carry electric charges, while the third component W3β€²W^{\prime}_3 can mix with the hypercharge U(1)YU(1)_Y gauge field and the third component of SU(2)LSU(2)_L; (4) Absence of tree level flavour changing neutral current is guaranteed by gauge symmetry; and {\it etc}. In this work, we concentrate on the mass spectra of scalar and gauge bosons in the model. Constraints from previous Zβ€²Z^\prime data at LEP and the Large Hadron Collider measurements of the Standard Model Higgs mass, its partial widths of Ξ³Ξ³\gamma\gamma and ZΞ³Z\gamma modes are discussed.Comment: 40 pages, 7 figures, version accepted in JHEP, relic density discussion adde
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