Cfxtrjtrk

藝術繪圖顯示出，早期宇宙時期的光束，在傳播通過宇宙空間之時，怎樣被大質量宇宙構造所產生的引力透鏡效應所偏轉，形成B模。（Credit: ESA）

B模偏振（B-mode polarization）是宇宙微波背景輻射的一種偏振信號。宇宙微波背景輻射的偏振圖樣可以分為兩個部分。一個是旋度為零的部分（類電場部分），稱為「E模偏振」，簡稱為「E模」，不具手徵性。2002年，度角尺度干涉儀（DASI）最先發現這種偏振。另一個是散度為零、旋度不為零的部分（類磁場部分），稱為「B模偏振」，簡稱為「B模」，具有手徵性。^[1]

宇宙學家預測存在兩種B模。第一種是在大爆炸短暫片刻後的宇宙暴脹過程中生成^[2]^[3]^[4]；第二種在後來由引力透鏡生成^[5]。

研究成果

2014年3月，BICEP2科學家團隊宣佈探測到第一種B模，符合早期宇宙暴脹期間所產生的引力波，純量-張量比為 ${displaystyle r=0.2_{-0.05}^{+0.07}}$ ^[6]^[7]。2015年1月30日，研究團隊承認對於資料的判讀錯誤，觀測到的信號無法排除掉銀河系輻射塵埃的影響，不足以證實這項結果就是早期宇宙的引力波所形成的B模偏振^[8]。

此前，南極望遠鏡已發現了第二種B模。這發現可能有助於檢驗有關宇宙起源的理論。科學家現在正在使用普朗克衛星所測得的數據做分析，希望能夠更進一步了解這些引力波。^[9]^[10]^[11]

參考文獻

^ Cosmic Microwave Background Polarization: The Next Key Toward the Origin of the Universe WebCite的存檔，存档日期2011-08-22, 2003, Yuki D. Takahashi

^ Seljak, U. Measuring Polarization in the Cosmic Microwave Background. Astrophysical Journal. June 1997, 482: 6. doi:10.1086/304123.

^ Seljak, U.; Zaldarriaga M. Signature of Gravity Waves in the Polarization of the Microwave Background. Phys. Rev.Lett. March 17, 1997, 78 (11). doi:10.1103/PhysRevLett.78.2054. 引文使用过时参数coauthors (帮助)

^ Kamionkowski, M.; Kosowsky A. & Stebbins A. A Probe of Primordial Gravity Waves and Vorticity. Phys. Rev.Lett. March 17, 1997, 78 (11). doi:10.1103/PhysRevLett.78.2058. 引文使用过时参数coauthors (帮助)

^ Zaldarriaga, M.; Seljak U. Gravitational lensing effect on cosmic microwave background polarization. Physical Review D. 2. July 15, 1998, 58. doi:10.1103/PhysRevD.58.023003. 引文使用过时参数coauthors (帮助)

^ Gravitational waves: have US scientists heard echoes of the big bang?. The Guardian. 2014-03-14 [2014-03-14].

^ http://www.nytimes.com/2014/03/18/science/space/detection-of-waves-in-space-buttresses-landmark-theory-of-big-bang.html?_r=0

^ Cho, Adrian. Curtain falls on controversial big bang result. Science. 2015-01-30.

^ ESA Planck. Planck Space Mission. Oct 22, 2013 [Oct 23, 2013].

^ NASA/Jet Propulsion Laboratory. Long-sought pattern of ancient light detected. ScienceDaily. 2013, October 22 [October 23, 2013]. 请检查|date=中的日期值 (帮助)

^ Hanson, D.; et al. Detection of B-Mode Polarization in the Cosmic Microwave Background with Data from the South Pole Telescope. Physical Review Letters. 14. Sep 30, 2013, 111. doi:10.1103/PhysRevLett.111.141301. 引文使用过时参数coauthors (帮助)

[1] Cosmic Microwave Background Polarization: The Next Key Toward the Origin of the Universe WebCite的存檔，存档日期2011-08-22, 2003, Yuki D. Takahashi

[2] Seljak, U. Measuring Polarization in the Cosmic Microwave Background. Astrophysical Journal. June 1997, 482: 6. doi:10.1086/304123.

[3] Seljak, U.; Zaldarriaga M. Signature of Gravity Waves in the Polarization of the Microwave Background. Phys. Rev.Lett. March 17, 1997, 78 (11). doi:10.1103/PhysRevLett.78.2054. 引文使用过时参数coauthors (帮助)

[4] Kamionkowski, M.; Kosowsky A. & Stebbins A. A Probe of Primordial Gravity Waves and Vorticity. Phys. Rev.Lett. March 17, 1997, 78 (11). doi:10.1103/PhysRevLett.78.2058. 引文使用过时参数coauthors (帮助)

[5] Zaldarriaga, M.; Seljak U. Gravitational lensing effect on cosmic microwave background polarization. Physical Review D. 2. July 15, 1998, 58. doi:10.1103/PhysRevD.58.023003. 引文使用过时参数coauthors (帮助)

[bmodes-6] Gravitational waves: have US scientists heard echoes of the big bang?. The Guardian. 2014-03-14 [2014-03-14].

[7] ttp://www.nytimes.com/2014/03/18/science/space/detection-of-waves-in-space-buttresses-landmark-theory-of-big-bang.html?_r=0

[8] Cho, Adrian. Curtain falls on controversial big bang result. Science. 2015-01-30.

[9] ESA Planck. Planck Space Mission. Oct 22, 2013 [Oct 23, 2013].

[10] NASA/Jet Propulsion Laboratory. Long-sought pattern of ancient light detected. ScienceDaily. 2013, October 22 [October 23, 2013]. 请检查|date=中的日期值 (帮助)

[11] Hanson, D.; et al. Detection of B-Mode Polarization in the Cosmic Microwave Background with Data from the South Pole Telescope. Physical Review Letters. 14. Sep 30, 2013, 111. doi:10.1103/PhysRevLett.111.141301. 引文使用过时参数coauthors (帮助)

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參考文獻

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