欧洲物理学家小组宣布宇宙微波背景调查BICEP2望远镜发现的B模偏振并不是由宇宙原初引力波造成的，而是银河系星际尘埃的干扰。
据Nature报道，来自欧洲空间局的物理学家小组宣布通过普朗克卫星的调查，宇宙大爆炸极早期引力波的发现确实是个失误，官方的研究报告将在下周公布。科学家认为宇宙微波背景调查BICEP2望远镜发现的B模偏振并不是由宇宙原初引力波造成的，而是银河系星际尘埃的干扰。宇宙微波背景是宇宙大爆炸时期遗留下来的古老辐射信息，距今可达140亿年之久。
在南极BICEP2望远镜发现宇宙极早期引力波信号之后，欧洲空间局普朗克卫星介入了调查，欧洲科学家使用这台空间望远镜的数据后发现，所谓的原初引力波证据并不充分，为了进一步论证这个发现，凯克望远镜也加入了鉴别工作。虽然我们否定了关于引力波信号的发现，但这个结果并没有令该领域的科学家感到惊讶，许多科学家之前就怀疑这个结论是否是正确的。
2014年3月，BICEP2望远镜的观测数据显示在宇宙大爆炸时期出现了引力波信号，科学家在调查宇宙微波背景辐射时探测到B模偏振，在此后的近一年的时间内，科学家一直在确定这个发现是否是可靠的。科学家原先认为，我们发现极早期引力波信号之后可以证实一些关于宇宙起源的假说，并揭示宇宙大爆炸后时空加速膨胀的机制。然而，银河系内存在的星际尘埃对观测形成了干扰，并产生了错误的结论。
为了证明银河系尘埃的干扰作用，科学家动用了普朗克空间望远镜调查背景辐射，其可以分析尘埃产生的影响，BICEP2项目的科学家约翰·科瓦奇来自哈佛大学，也是本项研究论文的第一作者，他认为当我们第一次发现这个信号时，仍然使用基于银河尘埃的背景辐射模型，事实上我们所观测的天区内真实尘埃辐射值要低得多，所以很遗憾我们没有能够发现宇宙膨胀的印记。
原文链接：http://tech.qq.com/a/20150201/005010.htm

A team of astronomers that last year reported evidence for gravitational waves from the early Universe has now withdrawn the claim. A joint analysis of data recorded by the team's South Pole telescope and by the European spacecraft Planck has revealed that the signal can be entirely attributed to dust in the Milky Way rather than having a more ancient, cosmic origin.
Nature special: Waves from the Big Bang
The European Space Agency (ESA) announced the long-awaited results on 30 January, a day after a summary of it had been unintentionally posted online by French members of the Planck team and then widely circulated before it was taken down.
The March finding was released by researchers using a radio telescope at the South Pole called BICEP2. It had hinged on finding a curlicue pattern in the polarization of the cosmic microwave background, the Big Bang's relic radiation. The team attributed the pattern to gravitational waves — ripples in space-time — generated during the earliest moment of the Universe when cosmologists believe the cosmos underwent a brief but tumultuous episode of expansion known as inflation. If detected, the primordial waves would confirm the highly successful but unproven theory of inflation.
But dust in the Milky Way also emits polarized light that can have the same curlicue pattern imprinted on it. Astronomers have suggested several times over the past year that the BICEP2 team had been fooled by that galactic signal (see 'Full-Galaxy dust map muddles search for gravitational waves'). The Planck-BICEP2 analysis confirms that BICEP2 cannot claim to have seen evidence of primordial gravitational waves.
In the joint analysis, the researchers overlaid data recorded by the BICEP2 telescope at a frequency of 150 gigahertz with data recorded from the same patch of sky by Planck at 353 Ghz, a frequency at which virtually all the polarized light comes from dust. (Planck also records polarization signals at lower frequencies). The two data sets proved a match — the region in which BICEP2 found its strongest signal is the same place that the Planck dust signal is strongest, indicating that the BICEP2 signal is due almost entirely to dust.
“This joint work has shown that the detection of primordial B-modes is no longer robust once the emission from Galactic dust is removed,” says Planck astronomer Jean-Loup Puget of the University of Paris-Sud in Orsay in the ESA press release. “So, unfortunately, we have not been able to confirm that the signal is an imprint of cosmic inflation.”
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“I no longer believe that BICEP2 detected the signal of’ gravitational waves,” says cosmologist Marc Kamionkowski of the Johns Hopkins University in Baltimore, Maryland, who is not a member of either team.
Planck researcher George Efstathiou of the University of Cambridge, UK, says that the conclusion is no surprise. “I don’t know why people are so excited,”he says. “There’s nothing dramatic here form the science point of view.”
Efstathiou characterized the 29 January leak as both “unfortunate” and “careless”. “The BICEP people felt that they had not handled the publicity right the first time” and that everyone was eager to make public the joint analysis in a more cautious manner.
Cosmologist Raphael Flauger of the Carnegie Mellon University in Pittsburgh, Pennsylvania, who was among the first researchers to put the BICEP2 findings into question, concurs with that view. “It is somewhat unfortunate that such an eagerly awaited result was presented to the public in this way,” he notes. He declined to discuss the details of the joint analysis, since the paper was not yet available, but he noted that “what is clear from these plots is that the levels of dust were underestimated in the BICEP2 results presented in March, in agreement with what was said in our paper” (see 'Gravitational wave discovery faces scrutiny').
“When we first detected this signal in our data, we relied on models for Galactic dust emission that were available at the time,” says John Kovac, a principal investigator of BICEP2 at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusett, in the ESA press release. “These seemed to indicate that the region of the sky chosen for our observations had dust polarisation much lower than the detected signal.”
The findings do not mean that it is impossible to find evidence of gravitational waves in the microwave backgrounnd — only that BICEP2 could not conclusively detect a signal amid the galactic noise.
“There is a clear path forward,” says Kamionkowski. “If we do more measurements of this type at multiple frequencies, we will be able to separate out the dust signal from the [primordial] signal precisely” and do a more thorough search for gravitational waves.

挽尊→_→另外lz不好好搞基发什么帖子啊←_←

去年这个发现好像是被当作宇宙暴涨的直接证据啊，从而还否定了一些大爆炸模型，原来是搞错了……看来实验想跟上理论的脚步太难了

唉，一个大新闻就这么弄没了

大赞4L！

糊糊说的对

thats disappointing!

有趣的事，文中提到， Marc Kamionkowski 不再相信此结果了。
据我朋友的信息，我猜测他大概可能是最后一个放弃此信心的宇宙学家了吧。可以想像，他会有多么失望。

可能会有更多更有意思的发现，这其实是好消息

我记得去年8月份左右就听到消息说planck数据分析没看到，认为有可能是没考虑lensing的影响。看来现在是BICEP自己也承认这事儿了……可惜啊……

难怪去年八月普朗克数据出来后没听过相应的报道，原来证伪了啊！

哎

近年来大新闻就是容易黄，要是过几天又宣布希格斯粒子发现也是接错线或什么干扰就黄了。