ALBERT

Beschreibung: A stochastic background of gravitational waves is expected to arise from a superposition of a large number of unresolved gravitational-wave sources of astrophysical and cosmological origin. It should carry unique signatures from the earliest epochs in the evolution of the Universe, inaccessible to standard astrophysical observations. Direct measurements of the amplitude of this background are therefore of fundamental importance for understanding the evolution of the Universe when it was younger than one minute. Here we report limits on the amplitude of the stochastic gravitational-wave background using the data from a two-year science run of the Laser Interferometer Gravitational-wave Observatory (LIGO). Our result constrains the energy density of the stochastic gravitational-wave background normalized by the critical energy density of the Universe, in the frequency band around 100 Hz, to be 〈6.9 x 10(-6) at 95% confidence. The data rule out models of early Universe evolution with relatively large equation-of-state parameter, as well as cosmic (super)string models with relatively small string tension that are favoured in some string theory models. This search for the stochastic background improves on the indirect limits from Big Bang nucleosynthesis and cosmic microwave background at 100 Hz.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉LIGO Scientific Collaboration & Virgo Collaboration -- Abbott, B P -- Abbott, R -- Acernese, F -- Adhikari, R -- Ajith, P -- Allen, B -- Allen, G -- Alshourbagy, M -- Amin, R S -- Anderson, S B -- Anderson, W G -- Antonucci, F -- Aoudia, S -- Arain, M A -- Araya, M -- Armandula, H -- Armor, P -- Arun, K G -- Aso, Y -- Aston, S -- Astone, P -- Aufmuth, P -- Aulbert, C -- Babak, S -- Baker, P -- Ballardin, G -- Ballmer, S -- Barker, C -- Barker, D -- Barone, F -- Barr, B -- Barriga, P -- Barsotti, L -- Barsuglia, M -- Barton, M A -- Bartos, I -- Bassiri, R -- Bastarrika, M -- Bauer, Th S -- Behnke, B -- Beker, M -- Benacquista, M -- Betzwieser, J -- Beyersdorf, P T -- Bigotta, S -- Bilenko, I A -- Billingsley, G -- Birindelli, S -- Biswas, R -- Bizouard, M A -- Black, E -- Blackburn, J K -- Blackburn, L -- Blair, D -- Bland, B -- Boccara, C -- Bodiya, T P -- Bogue, L -- Bondu, F -- Bonelli, L -- Bork, R -- Boschi, V -- Bose, S -- Bosi, L -- Braccini, S -- Bradaschia, C -- Brady, P R -- Braginsky, V B -- Brand, J F J van den -- Brau, J E -- Bridges, D O -- Brillet, A -- Brinkmann, M -- Brisson, V -- Van Den Broeck, C -- Brooks, A F -- Brown, D A -- Brummit, A -- Brunet, G -- Bullington, A -- Bulten, H J -- Buonanno, A -- Burmeister, O -- Buskulic, D -- Byer, R L -- Cadonati, L -- Cagnoli, G -- Calloni, E -- Camp, J B -- Campagna, E -- Cannizzo, J -- Cannon, K C -- Canuel, B -- Cao, J -- Carbognani, F -- Cardenas, L -- Caride, S -- Castaldi, G -- Caudill, S -- Cavaglia, M -- Cavalier, F -- Cavalieri, R -- Cella, G -- Cepeda, C -- Cesarini, E -- Chalermsongsak, T -- Chalkley, E -- Charlton, P -- Chassande-Mottin, E -- Chatterji, S -- Chelkowski, S -- Chen, Y -- Christensen, N -- Chung, C T Y -- Clark, D -- Clark, J -- Clayton, J H -- Cleva, F -- Coccia, E -- Cokelaer, T -- Colacino, C N -- Colas, J -- Colla, A -- Colombini, M -- Conte, R -- Cook, D -- Corbitt, T R C -- Corda, C -- Cornish, N -- Corsi, A -- Coulon, J-P -- Coward, D -- Coyne, D C -- Creighton, J D E -- Creighton, T D -- Cruise, A M -- Culter, R M -- Cumming, A -- Cunningham, L -- Cuoco, E -- Danilishin, S L -- D'Antonio, S -- Danzmann, K -- Dari, A -- Dattilo, V -- Daudert, B -- Davier, M -- Davies, G -- Daw, E J -- Day, R -- De Rosa, R -- Debra, D -- Degallaix, J -- Del Prete, M -- Dergachev, V -- Desai, S -- Desalvo, R -- Dhurandhar, S -- Di Fiore, L -- Di Lieto, A -- Di Paolo Emilio, M -- Di Virgilio, A -- Diaz, M -- Dietz, A -- Donovan, F -- Dooley, K L -- Doomes, E E -- Drago, M -- Drever, R W P -- Dueck, J -- Duke, I -- Dumas, J-C -- Dwyer, J G -- Echols, C -- Edgar, M -- Effler, A -- Ehrens, P -- Ely, G -- Espinoza, E -- Etzel, T -- Evans, M -- Evans, T -- Fafone, V -- Fairhurst, S -- Faltas, Y -- Fan, Y -- Fazi, D -- Fehrmann, H -- Ferrante, I -- Fidecaro, F -- Finn, L S -- Fiori, I -- Flaminio, R -- Flasch, K -- Foley, S -- Forrest, C -- Fotopoulos, N -- Fournier, J-D -- Franc, J -- Franzen, A -- Frasca, S -- Frasconi, F -- Frede, M -- Frei, M -- Frei, Z -- Freise, A -- Frey, R -- Fricke, T -- Fritschel, P -- Frolov, V V -- Fyffe, M -- Galdi, V -- Gammaitoni, L -- Garofoli, J A -- Garufi, F -- Genin, E -- Gennai, A -- Gholami, I -- Giaime, J A -- Giampanis, S -- Giardina, K D -- Giazotto, A -- Goda, K -- Goetz, E -- Goggin, L M -- Gonzalez, G -- Gorodetsky, M L -- Gobler, S -- Gouaty, R -- Granata, M -- Granata, V -- Grant, A -- Gras, S -- Gray, C -- Gray, M -- Greenhalgh, R J S -- Gretarsson, A M -- Greverie, C -- Grimaldi, F -- Grosso, R -- Grote, H -- Grunewald, S -- Guenther, M -- Guidi, G -- Gustafson, E K -- Gustafson, R -- Hage, B -- Hallam, J M -- Hammer, D -- Hammond, G D -- Hanna, C -- Hanson, J -- Harms, J -- Harry, G M -- Harry, I W -- Harstad, E D -- Haughian, K -- Hayama, K -- Heefner, J -- Heitmann, H -- Hello, P -- Heng, I S -- Heptonstall, A -- 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-- Lu, P -- Lubinski, M -- Lucianetti, A -- Luck, H -- Machenschalk, B -- Macinnis, M -- Mackowski, J-M -- Mageswaran, M -- Mailand, K -- Majorana, E -- Man, N -- Mandel, I -- Mandic, V -- Mantovani, M -- Marchesoni, F -- Marion, F -- Marka, S -- Marka, Z -- Markosyan, A -- Markowitz, J -- Maros, E -- Marque, J -- Martelli, F -- Martin, I W -- Martin, R M -- Marx, J N -- Mason, K -- Masserot, A -- Matichard, F -- Matone, L -- Matzner, R A -- Mavalvala, N -- McCarthy, R -- McClelland, D E -- McGuire, S C -- McHugh, M -- McIntyre, G -- McKechan, D J A -- McKenzie, K -- Mehmet, M -- Melatos, A -- Melissinos, A C -- Mendell, G -- Menendez, D F -- Menzinger, F -- Mercer, R A -- Meshkov, S -- Messenger, C -- Meyer, M S -- Michel, C -- Milano, L -- Miller, J -- Minelli, J -- Minenkov, Y -- Mino, Y -- Mitrofanov, V P -- Mitselmakher, G -- Mittleman, R -- Miyakawa, O -- Moe, B -- Mohan, M -- Mohanty, S D -- Mohapatra, S R P -- Moreau, J -- Moreno, G -- Morgado, N -- Morgia, A -- Morioka, T -- 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Rabeling, D S -- Radkins, H -- Raffai, P -- Raics, Z -- Rainer, N -- Rakhmanov, M -- Rapagnani, P -- Raymond, V -- Re, V -- Reed, C M -- Reed, T -- Regimbau, T -- Rehbein, H -- Reid, S -- Reitze, D H -- Ricci, F -- Riesen, R -- Riles, K -- Rivera, B -- Roberts, P -- Robertson, N A -- Robinet, F -- Robinson, C -- Robinson, E L -- Rocchi, A -- Roddy, S -- Rolland, L -- Rollins, J -- Romano, J D -- Romano, R -- Romie, J H -- Rover, C -- Rowan, S -- Rudiger, A -- Ruggi, P -- Russell, P -- Ryan, K -- Sakata, S -- Salemi, F -- Sandberg, V -- Sannibale, V -- Santamaria, L -- Saraf, S -- Sarin, P -- Sassolas, B -- Sathyaprakash, B S -- Sato, S -- Satterthwaite, M -- Saulson, P R -- Savage, R -- Savov, P -- Scanlan, M -- Schilling, R -- Schnabel, R -- Schofield, R -- Schulz, B -- Schutz, B F -- Schwinberg, P -- Scott, J -- Scott, S M -- Searle, A C -- Sears, B -- Seifert, F -- Sellers, D -- Sengupta, A S -- Sentenac, D -- Sergeev, A -- Shapiro, B -- Shawhan, P -- Shoemaker, D H -- Sibley, A -- Siemens, X -- Sigg, D -- Sinha, S -- Sintes, A M -- Slagmolen, B J J -- Slutsky, J -- van der Sluys, M V -- Smith, J R -- Smith, M R -- Smith, N D -- Somiya, K -- Sorazu, B -- Stein, A -- Stein, L C -- Steplewski, S -- Stochino, A -- Stone, R -- Strain, K A -- Strigin, S -- Stroeer, A -- Sturani, R -- Stuver, A L -- Summerscales, T Z -- Sun, K-X -- Sung, M -- Sutton, P J -- Swinkels, B L -- Szokoly, G P -- Talukder, D -- Tang, L -- Tanner, D B -- Tarabrin, S P -- Taylor, J R -- Taylor, R -- Terenzi, R -- Thacker, J -- Thorne, K A -- Thorne, K S -- Thuring, A -- Tokmakov, K V -- Toncelli, A -- Tonelli, M -- Torres, C -- Torrie, C -- Tournefier, E -- Travasso, F -- Traylor, G -- Trias, M -- Trummer, J -- Ugolini, D -- Ulmen, J -- Urbanek, K -- Vahlbruch, H -- Vajente, G -- Vallisneri, M -- Vass, S -- Vaulin, R -- Vavoulidis, M -- Vecchio, A -- Vedovato, G -- van Veggel, A A -- Veitch, J -- Veitch, P -- Veltkamp, C -- Verkindt, D -- Vetrano, F -- Vicere, A -- Villar, A -- Vinet, J-Y -- Vocca, H -- Vorvick, C -- Vyachanin, S P -- Waldman, S J -- Wallace, L -- Ward, H -- Ward, R L -- Was, M -- Weidner, A -- Weinert, M -- Weinstein, A J -- Weiss, R -- Wen, L -- Wen, S -- Wette, K -- Whelan, J T -- Whitcomb, S E -- Whiting, B F -- Wilkinson, C -- Willems, P A -- Williams, H R -- Williams, L -- Willke, B -- Wilmut, I -- Winkelmann, L -- Winkler, W -- Wipf, C C -- Wiseman, A G -- Woan, G -- Wooley, R -- Worden, J -- Wu, W -- Yakushin, I -- Yamamoto, H -- Yan, Z -- Yoshida, S -- Yvert, M -- Zanolin, M -- Zhang, J -- Zhang, L -- Zhao, C -- Zotov, N -- Zucker, M E -- Zweizig, J -- England -- Nature. 2009 Aug 20;460(7258):990-4. doi: 10.1038/nature08278.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Lists of participants and their affiliations appear at the end of the paper.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19693079" target="_blank"〉PubMed〈/a〉

Beschreibung: Einstein@Home aggregates the computer power of hundreds of thousands of volunteers from 192 countries to mine large data sets. It has now found a 40.8-hertz isolated pulsar in radio survey data from the Arecibo Observatory taken in February 2007. Additional timing observations indicate that this pulsar is likely a disrupted recycled pulsar. PSR J2007+2722's pulse profile is remarkably wide with emission over almost the entire spin period; the pulsar likely has closely aligned magnetic and spin axes. The massive computing power provided by volunteers should enable many more such discoveries.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Knispel, B -- Allen, B -- Cordes, J M -- Deneva, J S -- Anderson, D -- Aulbert, C -- Bhat, N D R -- Bock, O -- Bogdanov, S -- Brazier, A -- Camilo, F -- Champion, D J -- Chatterjee, S -- Crawford, F -- Demorest, P B -- Fehrmann, H -- Freire, P C C -- Gonzalez, M E -- Hammer, D -- Hessels, J W T -- Jenet, F A -- Kasian, L -- Kaspi, V M -- Kramer, M -- Lazarus, P -- van Leeuwen, J -- Lorimer, D R -- Lyne, A G -- Machenschalk, B -- McLaughlin, M A -- Messenger, C -- Nice, D J -- Papa, M A -- Pletsch, H J -- Prix, R -- Ransom, S M -- Siemens, X -- Stairs, I H -- Stappers, B W -- Stovall, K -- Venkataraman, A -- New York, N.Y. -- Science. 2010 Sep 10;329(5997):1305. doi: 10.1126/science.1195253. Epub 2010 Aug 12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Albert-Einstein-Institut, Max-Planck-Institut fur Gravitationsphysik, D-30167 Hannover, Germany. benjamin.knispel@aei.mpg.de〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20705813" target="_blank"〉PubMed〈/a〉

Beschreibung: Millisecond pulsars, old neutron stars spun up by accreting matter from a companion star, can reach high rotation rates of hundreds of revolutions per second. Until now, all such "recycled" rotation-powered pulsars have been detected by their spin-modulated radio emission. In a computing-intensive blind search of gamma-ray data from the Fermi Large Area Telescope (with partial constraints from optical data), we detected a 2.5-millisecond pulsar, PSR J1311-3430. This unambiguously explains a formerly unidentified gamma-ray source that had been a decade-long enigma, confirming previous conjectures. The pulsar is in a circular orbit with an orbital period of only 93 minutes, the shortest of any spin-powered pulsar binary ever found.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pletsch, H J -- Guillemot, L -- Fehrmann, H -- Allen, B -- Kramer, M -- Aulbert, C -- Ackermann, M -- Ajello, M -- de Angelis, A -- Atwood, W B -- Baldini, L -- Ballet, J -- Barbiellini, G -- Bastieri, D -- Bechtol, K -- Bellazzini, R -- Borgland, A W -- Bottacini, E -- Brandt, T J -- Bregeon, J -- Brigida, M -- Bruel, P -- Buehler, R -- Buson, S -- Caliandro, G A -- Cameron, R A -- Caraveo, P A -- Casandjian, J M -- Cecchi, C -- Celik, O -- Charles, E -- Chaves, R C G -- Cheung, C C -- Chiang, J -- Ciprini, S -- Claus, R -- Cohen-Tanugi, J -- Conrad, J -- Cutini, S -- D'Ammando, F -- Dermer, C D -- Digel, S W -- Drell, P S -- Drlica-Wagner, A -- Dubois, R -- Dumora, D -- Favuzzi, C -- Ferrara, E C -- Franckowiak, A -- Fukazawa, Y -- Fusco, P -- Gargano, F -- Gehrels, N -- Germani, S -- Giglietto, N -- Giordano, F -- Giroletti, M -- Godfrey, G -- Grenier, I A -- Grondin, M-H -- Grove, J E -- Guiriec, S -- Hadasch, D -- Hanabata, Y -- Harding, A K -- den Hartog, P R -- Hayashida, M -- Hays, E -- Hill, A B -- Hou, X -- Hughes, R E -- Johannesson, G -- Jackson, M S -- Jogler, T -- Johnson, A S -- Johnson, W N -- Kataoka, J -- Kerr, M -- Knodlseder, J -- Kuss, M -- Lande, J -- Larsson, S -- Latronico, L -- Lemoine-Goumard, M -- Longo, F -- Loparco, F -- Lovellette, M N -- Lubrano, P -- Massaro, F -- Mayer, M -- Mazziotta, M N -- McEnery, J E -- Mehault, J -- Michelson, P F -- Mitthumsiri, W -- Mizuno, T -- Monzani, M E -- Morselli, A -- Moskalenko, I V -- Murgia, S -- Nakamori, T -- Nemmen, R -- Nuss, E -- Ohno, M -- Ohsugi, T -- Omodei, N -- Orienti, M -- Orlando, E -- de Palma, F -- Paneque, D -- Perkins, J S -- Piron, F -- Pivato, G -- Porter, T A -- Raino, S -- Rando, R -- Ray, P S -- Razzano, M -- Reimer, A -- Reimer, O -- Reposeur, T -- Ritz, S -- Romani, R W -- Romoli, C -- Sanchez, D A -- Saz Parkinson, P M -- Schulz, A -- Sgro, C -- do Couto e Silva, E -- Siskind, E J -- Smith, D A -- Spandre, G -- Spinelli, P -- Suson, D J -- Takahashi, H -- Tanaka, T -- Thayer, J B -- Thayer, J G -- Thompson, D J -- Tibaldo, L -- Tinivella, M -- Troja, E -- Usher, T L -- Vandenbroucke, J -- Vasileiou, V -- Vianello, G -- Vitale, V -- Waite, A P -- Winer, B L -- Wood, K S -- Wood, M -- Yang, Z -- Zimmer, S -- New York, N.Y. -- Science. 2012 Dec 7;338(6112):1314-7. doi: 10.1126/science.1229054. Epub 2012 Oct 25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max-Planck-Institut fur Gravitationsphysik (Albert-Einstein-Institut), D-30167 Hannover, Germany. holger.pletsch@aei.mpg.de〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23112297" target="_blank"〉PubMed〈/a〉