44348672
Type II-P supernovae from the SDSS-II supernova survey and the standardized candle method
We apply the Standardized Candle Method (SCM) for Type II Plateau supernovae (SNe II-P), which relates the velocity of the ejecta of a SN to its luminosity during the plateau, to 15 SNe II-P discovered over the three season run of the Sloan Digital Sky Survey-II Supernova Survey. The redshifts of these SNe—0.027 0.01) as all of the current literature on the SCM combined. We find that the SDSS SNe have a very small intrinsic I-band dispersion (0.22 mag), which can be attributed to selection effects. When the SCM is applied to the combined SDSS-plus-literature set of SNe II-P, the dispersion increases to 0.29 mag, larger than the scatter for either set of SNe separately. We show that the standardization cannot be further improved by eliminating SNe with positive plateau decline rates, as proposed in Poznanski et al. We thoroughly examine all potential systematic effects and conclude that for the SCM to be useful for cosmology, the methods currently used to determine the Fe II velocity at day 50 must be improved, and spectral templates able to encompass the intrinsic variations of Type II-P SNe will be needed.
119248886
Subaru Spectroscopy of SDSS-II Supernovae
The Sloan Digital Sky Survey II (SDSS-II) Supernova Survey discovered Type Ia supernovae (SNe Ia) in an almost unexplored intermediate redshift range of $0.05 < z < 0.4$ and provided densely sampled multi-color light curves for SN candidates. Followup spectroscopy of this survey was carried out with the Subaru telescope and spectra of 71 SN Ia candidates were obtained. One spectrum was observed per candidate except for a peculiar variable. This paper presents the method for processing these spectra. The observed wavelength ranges of our spectra are 4000 to 9000 {\AA} for Year 2005 and 3600 to 9000 {\AA} for Year 2006. Most SN Ia spectra have signal to noise ratios (S/N) between 4 and 10 per 2 {\AA} averaged over the entire wavelength region. We developed a new code to extract the SN spectral component from spectra contaminated by the host galaxy. Of 71 SN Ia candidates, 59 are identified as normal SNe Ia and 3 are peculiar SNe Ia. The range of spectral phases varies from -7 days to +30 days from maximum brightness. There are also 7 SNe II, 1 possible hypernova and 1 AGN.
17597272
The Sloan Digital Sky Survey-II Photometry and Supernova IA Light Curves from the 2005 Data
We present ugriz light curves for 146 spectroscopically-confirmed or spectroscopically-probable Type Ia supernovae (SNe) from the 2005 season of the Sloan Digital Sky Survey-II Supernova (SN) survey. The light curves have been constructed using a photometric technique that we call scene modeling, which is described in detail here; the major feature is that SN brightnesses are extracted from a stack of images without spatial resampling or convolution of the image data. This procedure produces accurate photometry along with accurate estimates of the statistical uncertainty, and can be used to derive photometry taken with multiple telescopes. We discuss various tests of this technique that demonstrate its capabilities. We also describe the methodology used for the calibration of the photometry, and present calibrated magnitudes and fluxes for all of the spectroscopic SNe Ia from the 2005 season.
119204401
First-year Sloan Digital Sky Survey-II supernova results: consistency and constraints with other intermediate-redshift data sets
ABSTRACT We present an analysis of the luminosity distances of Type Ia Supernovae (SNe) from the Sloan Digital Sky Survey-II (SDSS-II) SN Survey in conjunction with other intermediate-redshift (z 97 per cent level from this single data set. We find good agreement between the SN and BAO distance measurements, both consistent with a Λ-dominated cold dark matter cosmology, as demonstrated through an analysis of the distance duality relationship between the luminosity (dL) and angular diameter (dA) distance measures. We then use these data to estimate w within this restricted redshift range (z < 0.4). Our most stringent result comes from the combination of all our intermediate-redshift data (SDSS-II SNe, BAO, ISW and redshift-space distortions), giving w = -0.81+0.16-0.18 (stat) +/- 0.15 (sys) and ΩM = 0.22+0.09-0.08 assuming a flat universe. This value of w and associated errors only change slightly if curvature is allowed to vary, consistent with constraints from the cosmic microwave background. We also consider more limited combinations of the geometrical (SN, BAO) and dynamical (ISW, redshift-space distortions) probes.
118626595
A MISMATCH IN THE ULTRAVIOLET SPECTRA BETWEEN LOW-REDSHIFT AND INTERMEDIATE-REDSHIFT TYPE Ia SUPERNOVAE AS A POSSIBLE SYSTEMATIC UNCERTAINTY FOR SUPERNOVA COSMOLOGY
We present Keck high-quality rest-frame ultraviolet (UV) through optical spectra of 21 Type Ia supernovae (SNe?Ia) in the redshift range 0.11 ? z ? 0.37 and a mean redshift of 0.22 that were discovered during the Sloan Digital Sky Survey-II (SDSS-II) SN Survey. Using the broadband photometry of the SDSS survey, we are able to reconstruct the SN host-galaxy spectral energy distributions (SEDs), allowing for a correction for the host-galaxy contamination in the SN Ia spectra. Comparison of composite spectra constructed from a subsample of 17 high-quality spectra to those created from a low-redshift sample with otherwise similar properties shows that the Keck/SDSS SNe?Ia have, on average, extremely similar rest-frame optical spectra but show a UV flux excess. This observation is confirmed by comparing synthesized broadband colors of the individual spectra, showing a difference in mean colors at the 2.4?-4.4? level for various UV colors. We further see a slight difference in the UV spectral shape between SNe with low-mass and high-mass host galaxies. Additionally, we detect a relationship between the flux ratio at 2770 and 2900 ? and peak luminosity that differs from that observed at low redshift. We find that changing the UV SED of an SN Ia within the observed dispersion can change the inferred distance moduli by ~0.1?mag. This effect only occurs when the data probe the rest-frame UV. We suggest that this discrepancy could be due to differences in the host-galaxy population of the two SN samples or to small-sample statistics.
117036676
Dependences of Type Ia Supernovae Lightcurve Parameters on the Host Galaxy Star Formation Rate and Metallicity
We present the dependences of the properties of type Ia Supernovae (SNe Ia) on their host galaxies by analyzing the multi-band lightcurves of 118 spectroscopically confirmed SNe Ia observed by the Sloan Digital Sky Survey (SDSS) Supernova Survey and the spectra of their host galaxies. We derive the equivalent width of the \rm{H}$\alpha$ emission line, star formation rate, and gas-phase metallicity from the spectra and compare these with the lightcurve widths and colors of SNe Ia. In addition, we compare host properties with the deviation of the observed distance modulus corrected for lightcurve parameters from the distance modulus determined by the best fit cosmological parameters. This allows us to investigate uncorrected systematic effects in the magnitude standardization. We find that SNe Ia in host galaxies with a higher star formation rate have synthesized on average a larger $^{56}$Ni mass and show wider lightcurves. The $^{56}$Ni mass dependence on metallicity is consistent with a prediction of Timmes et al. 2003 based on nucleosynthesis. SNe Ia in metal-rich galaxies ({$\log_{10}(O/H)+12>8.9$) have become 0.13 $\pm$ 0.06 magnitude brighter after corrections for their lightcurve widths and colors, which corresponds to up to 6% uncertainty in the luminosity distance. We investigate whether parameters for standardizing SN Ia maximum magnitude differ among samples with different host characteristics. The coefficient of the color term is larger by 0.67 $\pm$ 0.19 for SNe Ia in metal-poor hosts than those in metal-rich hosts when no color cuts are imposed.
14702420
Improved Convergence Proof of the Delta Expansion and Order Dependent Mappings
Abstract We improve and generalize in several accounts the recent rigorous proof of convergence of delta expansion–order dependent mappings (variational perturbation expansion) for the energy eigenvalues of quartic anharmonic oscillator. For the single-well oscillator the uniformity of convergence in g ∈[0, ∞] is proven. The convergence proof is extended also to complex values of g lying on a wide domain of the Riemann surface of E ( g ). Via the scaling relation a la Symanzik, this proves the convergence of delta expansion for the double well in the strong coupling regime (where the standard perturbation series is non Borel summable), as well as for the complex “energy eigenvalues” in certain metastable systems. Difficulties in extending the convergence proof to the cases of higher anharmonic oscillators are pointed out. Sufficient conditions for the convergence of delta expansion are summarized in the form of three general theorems, which should apply to a wide class of quantum mechanical and higher dimensional field theoretic systems.
1333458
Non-Abelian confinement near nontrivial conformal vacua
Abstract We discuss some aspects of confinement and dynamical symmetry breaking in the so-called non-Abelian Argyres–Douglas vacua, which occur very generally in supersymmetric theories. These systems are characterized by strongly-coupled non-Abelian monopoles and dyons; confinement and dynamical symmetry breaking are caused by the condensation of monopole composites, rather than by condensation of single weakly-coupled monopoles. In general, there are strong constraints on which kind of monopoles can appear as the infrared degrees of freedom, related to the proper realization of the global symmetry of the theory. Drawing analogies to some of the phenomena found here, we make a speculation on the ground state of the standard QCD.
122925113
On the consistency of supersymmetric instanton calculation in chiral gauge theories
Abstract Consistency of the algorithm of Amati and others for determining the properties of vacua in supersymmetric gauge theories, based on the instanton calculation at short distances, is further examined. When the summation over the degenerate vacua implicit in the instanton calculation is properly taken into account, the results for various condensates are found to be fully consistent in all cases studied. Our result strengthens the conclusion that supersymmetry is dynamically broken in some class of chiral gauge theories.
123767249
Anomalous Supersymmetry Transformation of Some Composite Operators in SQCD
Abstract The requirement that local products of fields be defined as appropriate limits of regularized operators, in a way compatible both with gauge invariance and with supersymmetry, leads to an anomalous supersymmetry transformation law of some (gauge-invariant) composite operators. We discuss an example of this and its application in supersymmetric QCD in four dimensions.
119423306
Avalanche in the valley (fermions, anomaly and unitarity in high-energy electroweak interactions)
Problems related to fermions, unitarity and chiral anomaly in high energy 
electroweak interactions, are investigated. Particular attention is paid to the 
correct functional integration over fermion fields in the background of 
instanton-anti\-instanton type configurations. This leads to an expansion of 
correlation functions in terms of a small parameter, $\rho/R$, when the 
instanton-antiinstanton separation ($R$) is large compared to their sizes 
($\rho$). Applying such a method to widely discussed cases of fermion-number 
violation in the electroweak theory, we conclude that there are no theoretical 
basis for expecting anomalous cross sections to become observable at energies 
in the $10$ TeV region.