1,449 research outputs found

    Cosmological Parameters from the Comparison of the 2MASS Gravity Field with Peculiar Velocity Surveys

    Full text link
    We compare the peculiar velocity field within 65 h−1h^{-1} Mpc predicted from 2MASS photometry and public redshift data to three independent peculiar velocity surveys based on type Ia supernovae, surface brightness fluctuations in ellipticals, and Tully-Fisher distances to spirals. The three peculiar velocity samples are each in good agreement with the predicted velocities and produce consistent results for \beta_{K}=\Omega\sbr{m}^{0.6}/b_{K}. Taken together the best fit βK=0.49±0.04\beta_{K} = 0.49 \pm 0.04. We explore the effects of morphology on the determination of β\beta by splitting the 2MASS sample into E+S0 and S+Irr density fields and find both samples are equally good tracers of the underlying dark matter distribution, but that early-types are more clustered by a relative factor b\sbr{E}/b\sbr{S} \sim 1.6. The density fluctuations of 2MASS galaxies in 8h−18 h^{-1} Mpc spheres in the local volume is found to be \sigma\sbr{8,K} = 0.9. From this result and our value of βK\beta_{K}, we find \sigma_8 (\Omega\sbr{m}/0.3)^{0.6} = 0.91\pm0.12. This is in excellent agreement with results from the IRAS redshift surveys, as well as other cosmological probes. Combining the 2MASS and IRAS peculiar velocity results yields \sigma_8 (\Omega\sbr{m}^/0.3)^{0.6} = 0.85\pm0.05.Comment: 11 pages, ApJ accepte

    FINANCIAL PERFORMANCE IN MEAT AND POULTRY MANUFACTURING AND WHOLESALING: AN HISTORICAL PERSPECTIVE

    Get PDF
    The financial performance of meat and poultry manufacturing and wholesaling firms is examined for the period from 1970 to 1986. Measures of liquidity, solvency, profitability, cash generation, and efficiency reported in the Robert Morris Associates Annual Statement Studies are used to examine relative performance across the different industries. The results suggest a similar performance in the wholesaling and manufacturing industries across the period in terms of liquidity. Profitability levels are similar for meat and poultry firms, although the poultry firms show a higher level of variability across the period. It appears that poultry firms leveraged themselves relatively more than did meat firms during the period. In terms of cash generation and efficiency the meat manufacturing industry performs slightly better than the other industries.Agricultural Finance,

    LIVESTOCK FUTURES MARKETS AND RATIONAL PRICE FORMATION: EVIDENCE FOR LIVE CATTLE AND LIVE HOGS

    Get PDF
    The efficiency of livestock futures markets continues to receive attention, particularly with regard to their forward pricing or forecasting ability. The purpose of this paper is to present a more general theory that encompasses the forward pricing concept. It is argued that futures contract prices for competitively produced nonstorable commodities, such as live cattle and live hogs, follow a rational formation process. Futures contract prices reflect expected market conditions when contracts are sufficiently close to the delivery month that the supply of the underlying commodity cannot be changed. However, prior to the period when future supplies are relatively fixed, futures contract prices should adjust to reflect the competitive equilibrium, where output price equals average costs of production. Presented evidence suggests that live cattle and live hog futures markets support the rational price formation hypothesis: prices for distant contracts reflect average costs of feeding. Implications for risk management strategies are considered.Demand and Price Analysis, Livestock Production/Industries,

    Maximum-Likelihood Comparisons of Tully-Fisher and Redshift Data. II. Results from an Expanded Sample

    Full text link
    This is the second in a series of papers in which we compare Tully-Fisher (TF) data from the Mark III Catalog with predicted peculiar velocities based on the IRAS galaxy redshift survey and gravitational instability theory, using a rigorous maximum likelihood method called VELMOD. In Paper I (Willick et al. 1997b), we we applied the method to a czLG≤3000cz_{LG} \leq 3000 km/sec, 838-galaxy TF sample and found βI=0.49±0.07,\beta_I=0.49\pm 0.07, where βI≡Ω0.6/bI\beta_I\equiv \Omega^{0.6}/b_I and bIb_I is the linear biasing parameter for IRAS galaxies. In this paper we increase the redshift limit to czLG=7500cz_{LG}=7500 km/sec, thereby enlarging the sample to 1876 galaxies. The expanded sample now includes the W91PP and CF subsamples of the Mark III catalog, in addition to the A82 and MAT subsamples already considered in Paper I. We implement VELMOD using both the forward and inverse forms of the TF relation, and allow for a more general form of the quadrupole velocity residual detected in Paper I. We find βI=0.50±0.04\beta_I=0.50\pm 0.04 (1-sigma error) at 300 km/sec smoothing of the IRAS-predicted velocity field. The fit residuals are spatially incoherent for βI=0.5,\beta_I=0.5, indicating that the IRAS plus quadrupole velocity field is a good fit to the TF data. If we eliminate the quadrupole we obtain a worse fit, but a similar value for βI\beta_I of 0.54±0.04.0.54\pm 0.04. Changing the IRAS smoothing scale to 500 km/sec has almost no effect on the best βI.\beta_I. We find evidence for a density-dependence of the small-scale velocity dispersion, σv(δg)≃(100+35δg)\sigma_v(\delta_g)\simeq (100 + 35 \delta_g) km/sec.Comment: Latex, 37 pages, 15 figures, uses modified apjpt4.st
    • …
    corecore