2,152 research outputs found

    Minimal Pati-Salam Model from String Theory Unification

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    We provide what we believe is the minimal three family N=1{\cal N} = 1 SUSY and conformal Pati-Salam Model from type IIB superstring theory. This Z3Z_3 orbifolded AdSS5\otimes S^5 model has long lived protons and has potential phenomenological consequences for LHC.Comment: 8 page

    Long-Wavelength Modes of Cosmological Scalar Fields

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    We give a numerical analysis of long-wavelength modes in the WKB approximation of cosmological scalar fields coupled to gravity via ξϕ2R\xi\phi^{2}R. Massless fields are coupled conformally at ξ=1/6\xi=1/6. Conformality can be preserved for fields of nonzero mass by shifting ξ\xi. We discuss implications for density perturbations.Comment: 10 pages, 10 figures, several stylistic improvement

    Primordial Black Holes, Hawking Radiation and the Early Universe

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    The 511 keV gamma emission from the galactic core may originate from a high concentration (1022\sim 10^{22}) of primordial black holes (PBHs) in the core each of whose Hawking radiation includes 1021\sim 10^{21} positrons per second. The PBHs we consider are taken as near the lightest with longevity greater than the age of the universe (mass 1012\sim 10^{12} kg; Schwarzschild radius 1\sim 1 fm). These PBHs contribute only a small fraction of cold dark matter, ΩPBH108\Omega_{PBH} \sim 10^{-8}. This speculative hypothesis, if confirmed implies the simultaneous discovery of Hawking radiation and an early universe phase transition.Comment: 4 Page

    Constraints on Deflation from the Equation of State of Dark Energy

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    In cyclic cosmology based on phantom dark energy the requirement that our universe satisfy a CBE-condition ({\it Comes Back Empty}) imposes a lower bound on the number NcpN_{\rm cp} of causal patches which separate just prior to turnaround. This bound depends on the dark energy equation of state w=p/ρ=1ϕw = p/\rho = -1 - \phi with ϕ>0\phi > 0. More accurate measurement of ϕ\phi will constrain NcpN_{\rm cp}. The critical density ρc\rho_c in the model has a lower bound ρc(109GeV)4\rho_c \ge (10^9 {\rm GeV})^4 or ρc(1018GeV)4\rho_c \ge (10^{18} {\rm GeV})^4 when the smallest bound state has size 101510^{-15}m, or 103510^{-35}m, respectively.Comment: 23 pages, 3 figures, typos fixe

    Mersenne Primes, Polygonal Anomalies and String Theory Classification

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    It is pointed out that the Mersenne primes Mp=(2p1)M_p=(2^p-1) and associated perfect numbers Mp=2p1Mp{\cal M}_p=2^{p-1}M_p play a significant role in string theory; this observation may suggest a classification of consistent string theories.Comment: 10 pages LaTe

    Alfalfa Cultivar Yield Test for South Dakota: 1998 Report

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    The South Dakota Alfalfa Cultivar Yield Test reports relative forage production characteristics for available cultivars at several locations in South Dakota. Alfalfas are entered in the test by seed companies and public breeders at their own discretion. A list of the cultivars and the companies marketing them is at the end of this bulletin

    Cultivar Test in South Dakota, 1990 Report: Alfalfa Yields

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    New alfalfa cultivars come on the market every year. Selecting the right one for your situation takes a little study on your part. From the SDSU Alfalfa Cultivar Yield Tests you can compare the critical forage production characteristics--yield, winterhardiness, and disease resistance--for available cultivars and experimental lines at several locations in South Dakot

    Cultivar Test in South Dakota, 1989 Report: Alfalfa Yields

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    Fifteen to 20 new alfalfa cultivars are released annually through public and commercial breeding programs. To select a cultivar for your operation, you will need information on forage yield, winterhardiness, and disease resistance. The alfalfa cultivar yield test of the Plant Science Department at SDSU determines relative forage production characteristics for available cultivars and experimental lines at several locations in South Dakota

    Cultivar Test in South Dakota, 1988 Report: Alfalfa Yields

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    About 15 new alfalfa cultivars are released each year. Many of these cultivars are on the market, and you need to know their forage yields under South Dakota conditions before you can select one for your operation. Such yield information is given here for available cultivars and experimental lines at several locations in the state
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