1,721,009 research outputs found
Perturbative Approach For Mass Varying Neutrinos Coupled To The Dark Sector In The Generalized Chaplygin Gas Scenario
Get PDFWe suggest a perturbative approach for generic choices for the universe equation of state and introduce a novel framework for studying mass varying neutrinos (MaVaN's) coupled to the dark sector. For concreteness, we examine the coupling between neutrinos and the underlying scalar field associated with the generalized Chaplygin gas (GCG), a unification model for dark energy and dark matter. It is shown that the application of a perturbative approach to MaVaN mechanisms translates into a constraint on the coefficient of a linear perturbation, which depends on the ratio between a neutrino energy dependent term and scalar field potential terms. We quantify the effects on the MaVaN sector by considering neutrino masses generated by the seesaw mechanism. After setting the GCG parameters in agreement with general cosmological constraints, we find that the squared speed of sound in the neutrino-scalar GCG fluid is naturally positive. In this scenario, the model stability depends on previously set up parameters associated with the equation of state of the universe. Our results suggest that the GCG is a particularly suitable candidate for constructing a stable MaVaN scenario. © 2008 The American Physical Society.778Riess, A.G., (1998) Astron. J., 116, p. 1009. , ANJOAA 0004-6256 10.1086/300499Perlmutter, S., (1999) Astrophys. J., 517, p. 565. , ASJOAB 0004-637X 10.1086/307221Astier, P., (2006) Astron. Astrophys., 447, p. 31. , AAEJAF 0004-6361 10.1051/0004-6361:20054185Burles, S., (2001) Astrophys. J., 552, p. 1. , ASJOAB 0004-637X 10.1086/320251De Bernardis, P., (2000) Nature (London), 404, p. 955. , NATUAS 0028-0836 10.1038/35010035Bennett, C.L., (2003) Astrophys. J. Suppl. Ser., 148, p. 1. , APJSA2 0067-0049 10.1086/377253Spergel, D.N., (2003) Astrophys. J. Suppl. Ser., 148, p. 175. , APJSA2 0067-0049 10.1086/377226Peacock, J.A., (2001) Nature (London), 410, p. 169. , NATUAS 0028-0836 10.1038/35065528Carlberg, R.G., (1999) Astrophys. J., 516, p. 552. , ASJOAB 0004-637X 10.1086/307121Turner, M.S., (2000) Phys. Scr., 85, p. 210. , PHSTBO 0031-8949 10.1238/Physica.Topical.085a00210Zlatev, I., Wang, L.M., Steinhardt, P.J., (1999) Phys. Rev. Lett., 82, p. 896. , PRLTAO 0031-9007 10.1103/PhysRevLett.82.896Wang, L.M., Caldwell, R.R., Ostriker, J.P., Steinhardt, P.J., (2000) Astrophys. J., 530, p. 17. , ASJOAB 0004-637X 10.1086/308331Steinhardt, P.J., Wang, L.M., Zlatev, I., (1999) Phys. Rev. D, 59, p. 123504. , PRVDAQ 0556-2821 10.1103/PhysRevD.59.123504Barreiro, T., Copeland, E.J., Nunes, N.J., (2000) Phys. Rev. D, 61, p. 127301. , PRVDAQ 0556-2821 10.1103/PhysRevD.61.127301Bertolami, O., Martins, P.J., (2000) Phys. Rev. D, 61, p. 064007. , PRVDAQ 0556-2821 10.1103/PhysRevD.61.064007Amendola, L., Tocchini-Valentini, D., (2002) Phys. Rev. D, 66, p. 043528. , PRVDAQ 0556-2821 10.1103/PhysRevD.66.043528Amendola, L., Tocchini-Valentini, D., (2002) Phys. Rev. D, 65, p. 063508. , PRVDAQ 0556-2821 10.1103/PhysRevD.65.063508Kamenshchik, A., Moschella, U., Pasquier, V., (2001) Phys. Lett. B, 511, p. 265. , PYLBAJ 0370-2693 10.1016/S0370-2693(01)00571-8Bilić, N., Tupper, G.B., Viollier, R.D., (2002) Phys. Lett. B, 535, p. 17. , PYLBAJ 0370-2693 10.1016/S0370-2693(02)01716-1Bento, M.C., Bertolami, O., Sen, A.A., (2002) Phys. Rev. D, 66, p. 043507. , PRVDAQ 0556-2821 10.1103/PhysRevD.66.043507Caldwell, R., Doran, M., Mueller, C., Schaefer, G., Wetterich, C., (2003) Astrophys. J., 591, p. 75. , ASJOAB 0004-637X 10.1086/376975Mota, D.F., Van De Bruck, C., (2004) Astron. Astrophys., 421, p. 71. , AAEJAF 0004-6361 10.1051/0004-6361:20041090Brookfield, A.W., Van De Bruck, C., Mota, D.F., Tocchini-Valentini, D., (2006) Phys. Rev. Lett., 96, p. 061301. , PRLTAO 0031-9007 10.1103/PhysRevLett.96.061301Brookfield, A.W., Van De Bruck, C., Mota, D.F., Tocchini-Valentini, D., (2006) Phys. Rev. D, 73, p. 083515. , PRVDAQ 0556-2821 10.1103/PhysRevD.73.083515Wetterich, C., (1988) Nucl. Phys., 302, p. 668. , NUPBBO 0550-3213 10.1016/0550-3213(88)90193-9Peebles, P.J.E., Ratra, B., (1988) Astrophys. J., 325, p. 17. , ASJOAB 0004-637X 10.1086/185100Ratra, B., Peebles, P.J.E., (1988) Phys. Rev. D, 37, p. 3406. , PRVDAQ 0556-2821 10.1103/PhysRevD.37.3406Bronstein, M., (1933) Phys. Z. Sowjetunion, 3, p. 73. , PHZSAL 0369-9811Bertolami, O., (1986) Nuovo Cimento Soc. Ital. Fis. B, 93, p. 36. , NIFBAP 0369-4100 10.1007/BF02728301Bertolami, O., (1986) Fortschr. Phys., 34, p. 829. , FPYKA6 0015-8208Ozer, M., Taha, O., (1986) Phys. Lett. B, 171, p. 363. , PYLBAJ 0370-2693 10.1016/0370-2693(86)91421-8Ozer, M., Taha, O., (1987) Nucl. Phys., 287, p. 776. , NUPBBO 0550-3213 10.1016/0550-3213(87)90128-3Chiba, T., Okabe, T., Yamaguchi, M., (2000) Phys. Rev. D, 62, p. 023511. , PRVDAQ 0556-2821 10.1103/PhysRevD.62.023511Armendariz-Picon, C., Mukhanov, V., Steinhardt, P.J., (2001) Phys. Rev. D, 63, p. 103510. , PRVDAQ 0556-2821 10.1103/PhysRevD.63.103510Schulz, A.E., White, M.J., (2001) Phys. Rev. D, 64, p. 043514. , PRVDAQ 0556-2821 10.1103/PhysRevD.64.043514Carroll, S.M., Hoffman, M., Trodden, M., (2003) Phys. Rev. D, 68, p. 023509. , PRVDAQ 0556-2821 10.1103/PhysRevD.68.023509Deffayet, C., Dvali, G.R., Gabadadze, G., (2002) Phys. Rev. D, 65, p. 044023. , PRVDAQ 0556-2821 10.1103/PhysRevD.65.044023Carroll, S.M., Duvvuri, V., Trodden, M., Turner, M.S., (2004) Phys. Rev. D, 70, p. 043528. , PRVDAQ 0556-2821 10.1103/PhysRevD.70.043528Amarzguioui, M., Elgaroy, O., Mota, D.F., Multamaki, T., (2006) Astron. Astrophys., 454, p. 707. , AAEJAF 0004-6361 10.1051/0004-6361:20064994Hung, P.Q., arXiv:hep-ph/0010126Gu, P., Wang, X., Zhang, X., (2003) Phys. Rev. D, 68, p. 087301. , PRVDAQ 0556-2821 10.1103/PhysRevD.68.087301Fardon, R., Nelson, A.E., Weiner, N., J. Cosmol. Astropart. Phys., 2004 (10), p. 005. , 1475-7516 10.1088/1475-7516/2004/10/005Bjaelde, O.E., J. Cosmol. Astropart. Phys., 2008 (1), p. 026. , 1475-7516 10.1088/1475-7516/2008/01/026Hannestad, S., (2005) Phys. Rev. Lett., 95, p. 221301. , PRLTAO 0031-9007 10.1103/PhysRevLett.95.221301Goobar, A., Hannestad, S., Mortsell, E., Tu, H., J. Cosmol. Astropart. Phys., 2006 (6), p. 019. , 1475-7516 10.1088/1475-7516/2006/06/019Skordis, C., Mota, D.F., Ferreira, P.G., Boehm, C., (2006) Phys. Rev. Lett., 96, p. 011301. , PRLTAO 0031-9007 10.1103/PhysRevLett.96.011301Hannestad, S., Raffelt, G.G., J. Cosmol. Astropart. Phys., 2006 (11), p. 016. , 1475-7516 10.1088/1475-7516/2006/11/016Lesgourgues, J., Pastor, S., (2006) Phys. Rep., 429, p. 307. , PRPLCM 0370-1573 10.1016/j.physrep.2006.04.001Takahashi, R., Tanimoto, M., J. High Energy Phys., 2006 (5), p. 021. , JHEPFG 1029-8479 10.1088/1126-6708/2006/05/021Peccei, R.D., (2005) Phys. Rev. D, 71, p. 023527. , PRVDAQ 0556-2821 10.1103/PhysRevD.71.023527Afshordi, N., Zaldarriaga, M., Kohri, K., (2005) Phys. Rev. D, 72, p. 065024. , PRVDAQ 0556-2821 10.1103/PhysRevD.72.065024Bento, M.C., Bertolami, O., Sen, A.A., (2003) Phys. Rev. D, 67, p. 063003. , PRVDAQ 0556-2821 10.1103/PhysRevD.67.063003Bento, M.C., Bertolami, O., Sen, A.A., (2003) Phys. Lett. B, 575, p. 172. , PYLBAJ 0370-2693 10.1016/j.physletb.2003.08.017Amendola, L., Finelli, F., Burigana, C., Carturan, D., J. Cosmol. Astropart. Phys., 2003 (7), p. 005. , 1475-7516 10.1088/1475-7516/2003/07/005Fabris, J.S., Gonçalves, S.V., De Souza, P.E., arXiv:astro-ph/0207430;Dev, A., Alcaniz, J.S., Jain, D., (2003) Phys. Rev. D, 67, p. 023515. , PRVDAQ 0556-2821 10.1103/PhysRevD.67.023515Gorini, V., Kamenshchik, A., Moschella, U., (2003) Phys. Rev. D, 67, p. 063509. , PRVDAQ 0556-2821 10.1103/PhysRevD.67.063509Makler, M., De Oliveira, S.Q., Waga, I., (2003) Phys. Lett. B, 555, p. 1. , PYLBAJ 0370-2693 10.1016/S0370-2693(03)00038-8Alcaniz, J.S., Jain, D., Dev, A., (2003) Phys. Rev. D, 67, p. 043514. , PRVDAQ 0556-2821 10.1103/PhysRevD.67.043514Bertolami, O., Sen, A.A., Sen, S., Silva, P.T., (2004) Mon. Not. R. Astron. Soc., 353, p. 329. , MNRAA4 0035-8711 10.1111/j.1365-2966.2004.08079.xBento, M.C., Bertolami, O., Sen, A.A., Santos, N.C., (2005) Phys. Rev. D, 71, p. 063501. , PRVDAQ 0556-2821 10.1103/PhysRevD.71.063501Silva, P.T., Bertolami, O., (2003) Astrophys. J., 599, p. 829. , ASJOAB 0004-637X 10.1086/379362Dev., A., Jain, D., Alcaniz, J.S., (2004) Astron. Astrophys., 417, p. 847. , AAEJAF 0004-6361 10.1051/0004-6361:20035627Bertolami, O., Silva, P.T., (2006) Mon. Not. R. Astron. Soc., 365, p. 1149. , MNRAA4 0035-8711Patt, B., Wilczek, F., arXiv:hep-ph/0605188;Bertolami, O., Rosenfeld, R., arXiv:0708.1784Bento, M.C., Bertolami, O., Rebouças, M.J., Silva, P.T., (2006) Phys. Rev. D, 73, p. 043504. , PRVDAQ 0556-2821 10.1103/PhysRevD.73.043504Barreiro, T., Bertolami, O., Torres, P., Bento, M.C., Bertolami, O., Sen, A.A., (2004) Phys. Rev. D, 70, p. 083519. , PRVDAQ 0556-2821 10.1103/PhysRevD.70.083519Gell-Mann, M., Ramond, P., Slansky, R., (1979) Complex Spinors and Unified Theories, , Supergravity (North-Holland, AmsterdamYanagida, T., (1979) Proceedings of the Workshop on Unified Theory and the Baryon Number of the Universe, , KEK, JapanMohapatra, R.N., (1986) Unification and Supersymmetry, , Springer-Verlag, BerlinArkani-Hamed, N., Dimopoulos, S., Dvali, G.R., March-Russell, J., (2001) Phys. Rev. D, 65, p. 024032. , PRVDAQ 0556-2821 10.1103/PhysRevD.65.024032Aharmim, B., (2005) Phys. Rev. C, 72, p. 055502. , PRVCAN 0556-2813 10.1103/PhysRevC.72.055502Ahmad, Q.R., (2002) Phys. Rev. Lett., 89, p. 011302. , PRLTAO 0031-9007 10.1103/PhysRevLett.89.011302Hosaka, J., (2006) Phys. Rev. D, 74, p. 032002. , PRVDAQ 0556-2821 10.1103/PhysRevD.74.032002Ashie, Y., (2005) Phys. Rev. D, 71, p. 112005. , PRVDAQ 0556-2821 10.1103/PhysRevD.71.112005Fukuda, S., (2002) Phys. Lett. B, 539, p. 179. , PYLBAJ 0370-2693 10.1016/S0370-2693(02)02090-7Boehm, F., (2001) Phys. Rev. D, 64, p. 112001. , PRVDAQ 0556-2821 10.1103/PhysRevD.64.112001Araki, T., (2005) Phys. Rev. Lett., 94, p. 081801. , PRLTAO 0031-9007 10.1103/PhysRevLett.94.081801Messier, M.D., arXiv:hep-ex/0606013, and references thereinKlapdor-Kleingrothaus, H.V., Krivosheina, I.V., Chkvorets, O., (2004) Phys. Lett. B, 586, p. 198. , PYLBAJ 0370-2693 10.1016/j.physletb.2004.02.025Ichikawa, K., Fukugita, M., Kawasaki, M., (2005) Phys. Rev. D, 71, p. 043001. , PRVDAQ 0556-2821 10.1103/PhysRevD.71.043001Fukugita, M., Ichikawa, K., Kawasaki, M., Lahav, O., (2006) Phys. Rev. D, 74, p. 027302. , PRVDAQ 0556-2821 10.1103/PhysRevD.74.027302Serpico, P.D., (2007) Phys. Rev. Lett., 98, p. 171301. , PRLTAO 0031-9007 10.1103/PhysRevLett.98.171301Kraus, C., (2005) Eur. Phys. J. C, 40, p. 447. , EPCFFB 1434-6044 10.1140/epjc/s2005-02139-
Dark energy–dark matter interaction and putative violation of the equivalence principle from the Abell cluster A586
No full textAbstractWe show that the Abell cluster A586 exhibits evidence of the interaction between dark matter and dark energy and argue that this interaction implies a violation of the equivalence principle. This violation is found in the context of two different models of dark energy–dark matter interaction. We also argue, based on the spherical symmetry of the Abell cluster A586 that skewness is not the most general quantity to test the equivalence principle
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
