1,372 research outputs found
New mechanism to cross the phantom divide
Recently, type Ia supernovae data appear to support a dark energy whose
equation of state crosses -1, which is a much more amazing problem than the
acceleration of the universe. We show that it is possible for the equation of
state to cross the phantom divide by a scalar field in the gravity with an
additional inverse power-law term of Ricci scalar in the Lagrangian. The
necessary and sufficient condition for a universe in which the dark energy can
cross the phantom divide is obtained. Some analytical solutions with or
are obtained. A minimal coupled scalar with different potentials,
including quadratic, cubic, quantic, exponential and logarithmic potentials are
investigated via numerical methods, respectively. All these potentials lead to
the crossing behavior. We show that it is a robust result which is hardly
dependent on the concrete form of the potential of the scalar.Comment: 11 pages, 5 figs, v3: several references added, to match the
published versio
The littlest Higgs model and Higgs boson associated production with top quark pair at high energy linear collider
In the parameter space allowed by the electroweak precision measurement data,
we consider the contributions of the new particles predicted by the littlest
Higgs() model to the Higgs boson associated production with top quark pair
in the future high energy linear collider(). We find that the
contributions mainly come from the new gauge bosons and . For
reasonable values of the free parameters, the absolute value of the relative
correction parameter can be significanly large,
which might be observed in the future experiment with .Comment: latex files, 13 pages, 3 figure
Quasifission at extreme sub-barrier energies
With the quantum diffusion approach the behavior of the capture cross-section
is investigated in the reactions Mo + Mo, Ru +
Ru, Pd + Pd, and Kr + Sn at deep
sub-barrier energies which are lower than the ground state energies of the
compound nuclei. Because the capture cross section is the sum of the complete
fusion and quasifission cross sections, and the complete fusion cross section
is zero at these sub-barrier energies, one can study experimentally the unique
quasifission process in these reactions after the capture.Comment: 3 pages, 3 figure
Measuring the Spectra of High Energy Neutrinos with a Kilometer-Scale Neutrino Telescope
We investigate the potential of a future kilometer-scale neutrino telescope
such as the proposed IceCube detector in the South Pole, to measure and
disentangle the yet unknown components of the cosmic neutrino flux, the prompt
atmospheric neutrinos coming from the decay of charmed particles and the
extra-galactic neutrinos, in the 10 TeV to 1 EeV energy range.
Assuming a power law type spectra,
, we quantify the discriminating
power of the IceCube detector and discuss how well we can determine magnitude
() as well as slope () of these two components of the high
energy neutrino spectrum, taking into account the background coming from the
conventional atmospheric neutrinos.Comment: 21 pages, 7 figure
Kaluza-Klein Cosmology With Modified Holographic Dark Energy
We investigate the compact Kaluza-Klein cosmology in which modified
holographic dark energy is interacting with dark matter. Using this scenario,
we evaluate equation of state parameter as well as equation of evolution of the
modified holographic dark energy. Further, it is shown that the generalized
second law of thermodynamics holds without any constraint.Comment: 13 pages, accepted for publication in Gen. Relativ. Gravi
Anomalous accelerations in spacecraft flybys of the Earth
[EN] The flyby anomaly is a persistent riddle in astrodynamics.
Orbital analysis in several flybys of the Earth
since the Galileo spacecraft flyby of the Earth in 1990 have
shown that the asymptotic post-encounter velocity exhibits
a difference with the initial velocity that cannot be attributed
to conventional effects. To elucidate its origin, we have developed
an orbital program for analyzing the trajectory of
the spacecraft in the vicinity of the perigee, including both
the Sun and the Moon¿s tidal perturbations and the geopotential
zonal, tesseral and sectorial harmonics provided by
the EGM96 model. The magnitude and direction of the
anomalous acceleration acting upon the spacecraft can be
estimated from the orbital determination program by comparing
with the trajectories fitted to telemetry data as provided
by the mission teams. This acceleration amounts to a
fraction of a mm/s2 and decays very fast with altitude. The
possibility of some new physics of gravity in the altitude
range for spacecraft flybys is discussed.Acedo Rodríguez, L. (2017). Anomalous accelerations in spacecraft flybys of the Earth. Astrophysics and Space Science. 362(12):1-15. doi:10.1007/s10509-017-3205-xS11536212Acedo, L.: Galaxies 3, 113 (2015)Acedo, L.: Mon. Not. R. Astron. Soc. 463(2), 2119 (2016)Acedo, L.: Adv. Space Res. 59(7), 1715 (2017). 1701.06939Acedo, L., Bel, L.: Astron. Nachr. 338(1), 117 (2017). 1602.03669Adler, S.L.: Int. J. Mod. Phys. A 25, 4577 (2010). 0908.2414 . doi: 10.1142/S0217751X10050706Adler, S.L.: In: Proceedings of the Conference in Honour of Murray Gellimann’s 80th Birthday, p. 352 (2011). doi: 10.1142/9789814335614_0032Anderson, J.D., Nieto, M.M.: In: Klioner, S.A., Seidelmann, P.K., Soffel, M.H. (eds.) Relativity in Fundamental Astronomy: Dynamics, Reference Frames, and Data Analysis. IAU Symposium, vol. 261, p. 189 (2010). doi: 10.1017/S1743921309990378Anderson, J.D., Laing, P.A., Lau, E.L., Liu, A.S., Nieto, M.M., Turyshev, S.G.: Phys. Rev. Lett. 81(14), 2858 (1998). gr-qc/0104064 . doi: 10.1103/PhysRevLett.81.2858Anderson, J.D., Laing, P.A., Lau, E.L., Liu, A.S., Nieto, M.M., Turyshev, S.G.: Phys. Rev. D 65(8), 082004 (2002). gr-qc/0104064 . doi: 10.1103/PhysRevD.65.082004Anderson, J.D., Campbell, J.K., Ekelund, J.E., Ellis, J., Jordan, J.F.: Phys. Rev. Lett. 100(9), 091102 (2008). doi: 10.1103/PhysRevLett.100.091102Atchison, J.A., Peck, M.A.: J. Guid. Control Dyn. 33, 1115 (2010). doi: 10.2514/1.47413Bertolami, O., Francisco, F., Gil, P.J.S.: Class. Quantum Gravity 33(12), 125021 (2016). 1507.08457 . doi: 10.1088/0264-9381/33/12/125021Bolton, S.J., Adriani, A., Adumitroaie, V., Allison, M., Anderson, J., Atreya, S., Bloxham, J., Brown, S., Connerney, J.E.P., DeJong, E., Folkner, W., Gautier, D., Grassi, D., Gulkis, S., Guillot, T., Hansen, C., Hubbard, W.B., Iess, L., Ingersoll, A., Janssen, M., Jorgensen, J., Kaspi, Y., Levin, S.M., Li, C., Lunine, J., Miguel, Y., Mura, A., Orton, G., Owen, T., Ravine, M., Smith, E., Steffes, P., Stone, E., Stevenson, D., Thorne, R., Waite, J., Durante, D., Ebert, R.W., Greathouse, T.K., Hue, V., Parisi, M., Szalay, J.R., Wilson, R.: Science 356, 821 (2017). doi: 10.1126/science.aal2108Cahill, R.T.: ArXiv e-prints (2008). 0804.0039Chamberlin, A., Yeomans, D., Giorgini, J., Chodas, P.: Horizons Ephemeris System (2016). http://ssd.jpl.nasa.gov/horizons.cgi . Accessed: 2016-10-27Chao, B.F.: C. R. Géosci. 338, 1123 (2006). doi: 10.1016/j.crte.2006.09.014Coddington, E., Levinson, N.: McGraw-Hill, New York (1955)Debono, I., Smoot, G.F.: Universe 2(4), 23 (2016). doi: 10.3390/universe2040023Desai, S.D.: J. Geophys. Res., Oceans 107(C11), 7 (2002). 3186. doi: 10.1029/2001JC001224Dickey, J.O., Bender, P.L., Faller, J.E., Newhall, X.X., Ricklefs, R.L., Ries, J.G., Shelus, P.J., Veillet, C., Whipple, A.L., Wiant, J.R., Williams, J.G., Yoder, C.F.: Science 265, 482 (1994). doi: 10.1126/science.265.5171.482Dyson, F.W., Eddington, A.S., Davidson, C.: Philos. Trans. R. Soc. Lond., Ser. A 220, 291 (1920). doi: 10.1098/rsta.1920.0009Everitt, C.W.F., et al.: Phys. Rev. Lett. 221101(106) (2011)Feng, J.L., Fornal, B., Galon, I., Gardner, S., Smolinsky, J., Tait, T.M.P., Tanedo, P.: Phys. Rev. Lett. 117, 071803 (2016). 1604.07411 . doi: 10.1103/PhysRevLett.117.071803Folkner, W.M., Williams, J.G., Boggs, D.H., Park, R.S., Kuchynka, P.: IPN Prog. Rep. 42(196) (2014)Fornberg, B.: Math. Comput. 51(184), 699 (1988). doi: 10.1090/S0025-5718-1988-0935077-0Franklin, A., Fischback, E.: The Rise and Fall of the Fifth Force. Discovery, Pursuit, and Justification in Modern Physics, second edition. Springer, New York (2016)Giorgini, J.D.: Personal communication (2015)Hackmann, E., Laemmerzahl, C.: In: 38th COSPAR Scientific Assembly. COSPAR Meeting, vol. 38, p. 3 (2010)Hafele, J.C.: ArXiv e-prints (2009). 0904.0383ICGEM: International Center for Global Gravity Field Models. http://icgem.gfz-potsdam.de/tom_longtimeIERS: In: Petit, G., Luzum, B. (eds.) IERS Conventions (2010), p. 1. Verlag des Bundesamts für Kartographie und Geodäsie, Frankfurt am Main (2010)Iess, L., Asmar, S.: Int. J. Mod. Phys. D 16, 2117 (2007). doi: 10.1142/S0218271807011449Iess, L., Asmar, S., Tortora, P.: Acta Astronaut. 65, 666 (2009). doi: 10.1016/j.actaastro.2009.01.049Iess, L., Di Benedetto, M., James, M., Mercolino, M., Simone, L., Tortora, P.: Acta Astronaut. 94, 699 (2014). doi: 10.1016/j.actaastro.2013.06.011Iorio, L.: Sch. Res. Exch. (2009). 0811.3924 . doi: 10.3814/2009/807695Iorio, L.: Astron. J. 142, 68 (2011a). 1102.4572 . doi: 10.1088/0004-6256/142/3/68Iorio, L.: Mon. Not. R. Astron. Soc. 415, 1266 (2011b). 1102.0212Iorio, L.: Europhys. Lett. (2011c). 1105.4145 . doi: 10.1209/0295-5075/96/30001Iorio, L.: Adv. Space Res. 54(11), 2441 (2014a). 1311.4218 . doi: 10.1016/j.asr.2014.06.035Iorio, L.: Galaxies 2, 259 (2014b). 1404.6537 . doi: 10.3390/galaxies2020259Iorio, L.: Universe 1(1), 38 (2015a). doi: 10.3390/universe1010038Iorio, L.: Int. J. Mod. Phys. D 24, 1530015 (2015b). 1412.7673Iorio, L., Giudice, G.: New Astron. 11, 600 (2006). gr-qc/0601055Iorio, L., Lichtenegger, H.I.M., Ruggiero, M.L., Corda, C.: Astrophys. Space Sci. 331, 351 (2011). 1009.3225 . doi: 10.1007/s10509-010-0489-5Jouannic, B., Noomen, R., van den IJSel, J.A.A.: In: Proceedings of the 25th International Symposium on Space Flight Dynamics ISSFD, Munich, Germany (2015)Kennefick, D.: Phys. Today 62, 37 (2009). doi: 10.1063/1.3099578King-Hele, D.: Satellite Orbits in an Atmosphere. Theory and Applications. Blackie and Son Ltd., Glasgow (1987)Lämmerzahl, C., Preuss, O., Dittus, H.: In: Dittus, H., Lammerzahl, C., Turyshev, S.G. (eds.) Lasers, Clocks and Drag-Free Control: Exploration of Relativistic Gravity in Space. Astrophysics and Space Science Library, vol. 349, p. 75 (2008). doi: 10.1007/978-3-540-34377-6_3Le Verrier, U.: C. R. Hebd. Acad. Sci. 49, 379 (1859)Lemoine, F.G.E.A.: NASA/TP-1998-206861 (1998)Lewis, R.A.: In: Robertson, G.A. (ed.) American Institute of Physics Conference Series. American Institute of Physics Conference Series, vol. 1103, p. 226 (2009). doi: 10.1063/1.3115499Longair, M.: Philos. Trans. R. Soc., Math. Phys. Eng. Sci. (2015). doi: 10.1098/rsta.2014.0287McCulloch, M.E.: Mon. Not. R. Astron. Soc. 389, 57 (2008). 0806.4159 . doi: 10.1111/j.1745-3933.2008.00523.xMoe, M.M., Wallace, S.D., Moe, K.: In: Washington DC American Geophysical Union Geophysical Monograph Series, vol. 87, p. 349 (1995). doi: 10.1029/GM087p0349Murphy, E.M.: Phys. Rev. Lett. 83, 1890 (1998). doi: 10.1103/PhysRevLett.83.1890Naval Observatory: Dept. of the Navy, USA (2009)Newcomb, S.: Tables of the Four Inner Planets. Government Printing Office, Washington (1895)Nyambuya, G.G.: ArXiv e-prints (2008). 0803.1370Nyambuya, G.G.: New Astron. 57, 22 (2017). doi: 10.1016/j.newast.2017.06.001Páramos, J., Hechenblaikner, G.: Adv. Space Res. 79–80(7), 76 (2013). 1210.7333v1Peskin, M.E., Schroeder, D.V.: An Introduction to Quantum Field Theory. Westview Press, Perseus Books Group, London (1995)Pinheiro, M.J.: Phys. Lett. A 378, 3007 (2014). 1404.1101Pinheiro, M.J.: Mon. Not. R. Astron. Soc. 461(4), 3948 (2016)Renzetti, G.: Cent. Eur. J. Phys. 11, 531 (2013). doi: 10.2478/s11534-013-0189-1Rievers, B., Lämmerzahl, C.: Ann. Phys. 523, 439 (2011). 1104.3985 . doi: 10.1002/andp.201100081Roseveare, N.T.: Mercury’s Perihelion, from Le Verrier to Einstein. Clarendon Press, Wotton-under-Edge (1982)Rubincam, D.P.: Icarus 148, 2 (2000). doi: 10.1006/icar.2000.6485Standish, E.M.: In: Macias, A., Lämmerzahl, C., Camacho, A. (eds.) Recent Developments in Gravitation and Cosmology. American Institute of Physics Conference Series, vol. 977, p. 254 (2008). doi: 10.1063/1.2902789Standish, E.M.: In: Klioner, S.A., Seidelmann, P.K., Soffel, M.H. (eds.) Relativity in Fundamental Astronomy: Dynamics, Reference Frames, and Data Analysis. IAU Symposium, vol. 261, p. 179 (2010). doi: 10.1017/S1743921309990354Thompson, P.F., Abrahamson, M., Ardalan, S., Bordi, J.: In: 24th AAS/AIAA Space Flight Mechanics Meeting, Santa Fe, New Mexico, January 26–30, 2014 (2014). http://hdl.handle.net/2014/45519Turyshev, S.G., Toth, V.T.: Living Rev. Relativ. (2010). 1001.3686 . doi: 10.12942/lrr-2010-4Turyshev, S.G., Toth, V.T., Kinsella, G., Lee, S.-C., Lok, S.M., Ellis, J.: Phys. Rev. Lett. 108(24), 241101 (2012). 1204.2507 . doi: 10.1103/PhysRevLett.108.241101Varieschi, G.U.: Gen. Relativ. Gravit. 46, 1741 (2014). 1401.6503 . doi: 10.1007/s10714-014-1741-zWilhelm, K., Dwivedi, B.N.: Astrophys. Space Sci. 358, 18 (2015). doi: 10.1007/s10509-015-2413-5Will, C.M.: Living Rev. Relativ. 3(9) (2006)Will, C.M.: Class. Quantum Gravity (2015). doi: 10.1098/rsta.2014.0287Will, C.M.: In: Peron, R., Colpi, M., Gorini, V., Moschella, U. (eds.) Gravity: Where Do We Stand? Astrophysics and Space Science Library, vol. 349, p. 9 (2016). doi: 10.1007/978-3-319-20224-2_2Williams, J.G., Boggs, D.H.: Celest. Mech. Dyn. Astron. 126, 89 (2016). doi: 10.1007/s10569-016-9702-3Williams, J.G., Dickey, J.O.: In: Noomen, R., Klosko, S., Noll, C., Pearlman, M. (eds.) Proceedings of 13th International Workshop on Laser Ranging, p. 75 (2003). http://cddisa.gsfc.nasa.gov/lw13/lw_proceedings.htmlWilliams, J.G., Newhall, X.X., Dickey, J.O.: Phys. Rev. D 53, 6730 (1996). doi: 10.1103/PhysRevD.53.6730Williams, J.G., Turyshev, S.G., Boggs, D.H.: Phys. Rev. Lett. 93(26), 261101 (2004). gr-qc/0411113 . doi: 10.1103/PhysRevLett.93.261101Williams, J.G., Turyshev, S.G., Boggs, D.H.: Planet. Sci. 3, 2 (2014). doi: 10.1186/s13535-014-0002-5Williams, J.G., Boggs, D.H., Yoder, C.F., Ratcliff, J.T., Dickey, J.O.: J. Geophys. Res. 106, 27933 (2001). doi: 10.1029/2000JE001396Wolfram, S.: The Mathematica Book, fifth edition. Wolfram Media, Champaign (2003
The accelerated scaling attractor solution of the interacting agegraphic dark energy in Brans-Dicke theory
We investigate the interacting agegraphic dark energy in Brans-Dicke theory
and introduce a new series general forms of dark sector coupling. As examples,
we select three cases involving a linear interaction form (Model I) and two
nonlinear interaction form (Model II and Model III). Our conclusions show that
the accelerated scaling attractor solutions do exist in these models. We also
find that these interacting agegraphic dark energy modes are consistent with
the observational data. The difference in these models is that nonlinear
interaction forms give more approached evolution to the standard CDM
model than the linear one. Our work implies that the nonlinear interaction
forms should be payed more attention.Comment: 9 pages, 10 figures, accepted in Eur. Phys. J.
Dynamical parton distributions of the nucleon and very small-x physics
Utilizing recent DIS measurements (F_{2,L}) and data on dilepton and
high-E_{T} jet production we determine the dynamical parton distributions of
the nucleon generated radiatively from valence-like positive input
distributions at optimally chosen low resolution scales. These are compared
with `standard' distributions generated from positive input distributions at
some fixed and higher resolution scale. It is shown that up to the next to
leading order NLO(\bar{MS}, DIS) of perturbative QCD considered in this paper,
the uncertainties of the dynamical distributions are, as expected, smaller than
those of their standard counterparts. This holds true in particular in the
presently unexplored extremely small-x region relevant for evaluating ultrahigh
energy cross sections in astrophysical applications. It is noted that our new
dynamical distributions are compatible, within the presently determined
uncertainties, with previously determined dynamical parton distributions.Comment: 21 pages, 2 tables, 16 figures, v2: added Ref.[60], replaced Fig.
Quark Imaging in the Proton Via Quantum Phase-Space Distributions
We develop the concept of quantum phase-space (Wigner) distributions for
quarks and gluons in the proton. To appreciate their physical content, we
analyze the contraints from special relativity on the interpretation of elastic
form factors, and examine the physics of the Feynman parton distributions in
the proton's rest frame. We relate the quark Wigner functions to the
transverse-momentum dependent parton distributions and generalized parton
distributions, emphasizing the physical role of the skewness parameter. We show
that the Wigner functions allow to visualize quantum quarks and gluons using
the language of the classical phase space. We present two examples of the quark
Wigner distributions and point out some model-independent features.Comment: 20 pages with 3 fiture
Charged lepton Flavor Violation in Supersymmetry with Bilinear R-Parity Violation
The simplest unified extension of the Minimal Supersymmetric Standard Model
with bi-linear R-parity violation naturally predicts a hierarchical neutrino
mass spectrum, suitable to explain atmospheric and solar neutrino fluxes. We
study whether the individual violation of the lepton numbers L_{e,mu,tau} in
the charged sector can lead to measurable rates for BR(mu->e gamma)and
$BR(tau-> mu gamma). We find that some of the R-parity violating terms that are
compatible with the observed atmospheric neutrino oscillations could lead to
rates for mu->e gamma measurable in projected experiments. However, the Delta
m^2_{12} obtained for those parameters is too high to be compatible with the
solar neutrino data, excluding therefore the possibility of having measurable
rates for mu->e gamma in the model.Comment: 29 pages, 8 figures. Constraint from solar neutrino data included,
conclusions changed respect v
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