强悍的MINE
可以算出任何两个随机变量之间的相关性,而不在乎它们是什么样的相关函数。这比p-value啥的要适用的范围广很多。它可以理论上证明,如果是相关的变量,所得到的MIC值就会趋近于1,如果是独立的,当随机事例足够多的时候,就会趋近于0. (那如果y和x1,x2共同相关,但只计算了y和x1的MIC呢?我估计是趋近于一个0到1之间的某个值。)
http://www.exploredata.net/Downloads/MINE-Application
不知道是不是只能算两两间的。
伽玛暴(Gamma-Ray Burst)笔记。记录有关伽玛暴的新文章,另外也包括看的老文章、自己的想法、以及跟天文相关的一些东西。 Feel free to leave me a message by comments or by email.
可以算出任何两个随机变量之间的相关性,而不在乎它们是什么样的相关函数。这比p-value啥的要适用的范围广很多。它可以理论上证明,如果是相关的变量,所得到的MIC值就会趋近于1,如果是独立的,当随机事例足够多的时候,就会趋近于0. (那如果y和x1,x2共同相关,但只计算了y和x1的MIC呢?我估计是趋近于一个0到1之间的某个值。)
http://www.exploredata.net/Downloads/MINE-Application
不知道是不是只能算两两间的。
Labels: 8.f statistics, 8.g R, 9.1 notes and notations
参考: http://f.dataguru.cn/thread-674-1-1.html
统计只能给出变量之间是否有相关性,但不能判断是因果关系还是平行关系,判断只能是人对内部规律的理解。
Labels: 8.f statistics, 8.g R, 9.1 notes and notations
貌似翻译成稀疏波,在Kobayashi & Sari的正反激波文章中(http://labs.adsabs.harvard.edu/adsabs/abs/2000ApJ...542..819K/)提到正反激波结束后会有稀疏波,但一直没弄懂什么意思。
主要内容:
在密的star claster 里的比较小质量的黑洞,不会马上 形成吸积盘(吸积盘的吸入速度太慢),而是由于黑洞的质量小不占主导,在cluster中在做 无规运动,不 形成盘,物质直接 掉入,快速增长质量。而由于当地密度太大,光深大,引力能释放产生的光子出不来,所以也看不到。
话说这篇文章出来,是不是意味着AGN中黑洞质量来源之谜就解决了?
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Labels: 8.2 BH accretion, 8.3 Cosmology
主要内容:
有人想做量子望远镜了,就是接收的地方考虑光子的量子效应。
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他说克隆一些光子就可以增加角分辨率了(我表示怀疑),如果这样,以后就不用做大望远镜了,只用拼命地克隆就可以了? |
In the 20th century, quantum mechanics connected the particle and wave concepts of light and thereby made mechanisms accessible that had never been imagined before. Processes such as stimulated emission and quantum entanglement have revolutionized modern technology. But even though astronomical observations rely on novel technologies, the optical layout of telescopes has fundamentally remained unchanged. While there is no doubt that Huyghens and Newton would be astounded by the size of our modern telescopes, they would nevertheless understand their optical design. The time may now have come to consider quantum telescopes, that make use of the fundamental scientific changes brought along by quantum mechanics. While one aim is to entertain our reader, our main purpose is to explore the possible future evolution of telescopes.
Comments: | in press with Astronomy & Geophysics, to be published in the June issue |
Subjects: | Instrumentation and Methods for Astrophysics (astro-ph.IM) |
Cite as: | arXiv:1403.6681 [astro-ph.IM] |
(or arXiv:1403.6681v1 [astro-ph.IM] for this version) |
Labels: 4.7 instruments, 8.5 astronomy
主要内容:
荣锋今天介绍了一个很有意思的源,HLX-1,光度很高,被认为可能是中等质量黑洞的候选体。还能看到大约1年的爆发周期!主流模型就是一个WR星以一年的周期绕着这个IMBH转,接近的时候有物质从WR星过去,产生爆发现象。
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Labels: 8 non-GRB
主要内容:
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右边是扣除别的东西后留下来的,说延伸到10°。
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Title: | The Characterization of the Gamma-Ray Signal from the Central Milky Way: A Compelling Case for Annihilating Dark Matter | |
Authors: | Daylan, Tansu; Finkbeiner, Douglas P.; Hooper, Dan; Linden, Tim; Portillo, Stephen K. N.; Rodd, Nicholas L.; Slatyer, Tracy R. | |
Publication: | eprint arXiv:1402.6703 | |
Publication Date: | 02/2014 | |
Origin: | ARXIV | |
Keywords: | Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Extragalactic Astrophysics, Astrophysics - Galaxy Astrophysics, High Energy Physics - Phenomenology, High Energy Physics - Theory | |
Comment: | 26 pages, 28 figures | |
Bibliographic Code: | 2014arXiv1402.6703D |
Bibtex entry for this abstract Preferred format for this abstract (see Preferences) |
主要内容:
作者认为大质量恒星坍缩成黑洞的时候可以并不真的成为黑洞,而是由于所谓的“量子引力压”抵抗住了引力(注意在视界面以内),从而称为普朗克星。这个量子引力压可以产生反弹,然后以霍金辐射的形式,看起来像黑洞蒸发。所观测到的可能就是一个伽马暴,当然不是大多数和超新星成协的伽马暴。因为从坍缩到反弹虽然在当地系可以是很短的时间,但是由于巨大的引力红移,在观测者看是一个超级长的时间,可能就和霍金算的黑洞蒸发的时间一样吧,不过如果一样的话现在就看不到,太长了。
作者所要解决的问题是恒星在坍缩成黑洞,然后再蒸发的过程中信息丢失了。但如果没有奇点,信息就不丢失。
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文章信息:
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Title: | Planck stars | |
Authors: | Rovelli, Carlo; Vidotto, Francesca | |
Publication: | eprint arXiv:1401.6562 | |
Publication Date: | 01/2014 | |
Origin: | ARXIV | |
Keywords: | General Relativity and Quantum Cosmology, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Theory | |
Comment: | 6 pages, 3 figures. Nice paper | |
Bibliographic Code: | 2014arXiv1401.6562R |
Bibtex entry for this abstract Preferred format for this abstract (see Preferences) |
Labels: 5.5 Quantum Gravity
主要内容:
说第一个是反向激波,第二个是外激波。第一个peak是反向激波nu_a穿过射电频率的时候。
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红色的点是AMI新观测的,包括早期的一个上升。
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Title: | Probing the Bright Radio Flare and Afterglow of GRB 130427A with the Arcminute Microkelvin Imager | |
Authors: | Anderson, G. E.; van der Horst, A. J.; Staley, T. D.; Fender, R. P.; Wijers, R. A. M. J.; Scaife, A. M. M.; Rumsey, C.;Titterington, D. J.; Rowlinson, A.; Saunders, R. D. E. | |
Publication: | eprint arXiv:1403.2217 | |
Publication Date: | 03/2014 | |
Origin: | ARXIV | |
Keywords: | Astrophysics - High Energy Astrophysical Phenomena | |
Comment: | Accepted for publication in MNRAS | |
Bibliographic Code: | 2014arXiv1403.2217A |
Bibtex entry for this abstract Preferred format for this abstract (see Preferences) |
主要内容:
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Title: | Blue Supergiant Model for Ultra-long Gamma-Ray Burst with Superluminous-supernova-like Bump | |
Authors: | Nakauchi, Daisuke; Kashiyama, Kazumi; Suwa, Yudai; Nakamura, Takashi | |
Affiliation: | AA(Department of Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan), AB(Department of Astronomy & Astrophysics, Department of Physics, Center for Particle & Gravitational Astrophysics, Pennsylvania State University, University Park, PA 16802, USA), AC(Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan), AD(Department of Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan) | |
Publication: | The Astrophysical Journal, Volume 778, Issue 1, article id. 67, | |
Publication Date: | 11/2013 | |
Origin: | IOP | |
Astronomy Keywords: | gamma-ray burst: general, gamma-ray burst: individual: GRB 111209A GRB 101225A GRB121027A | |
DOI: | 10.1088/0004-637X/778/1/67 | |
Bibliographic Code: | 2013ApJ...778...67N |
Bibtex entry for this abstract Preferred format for this abstract (see Preferences) |
Labels: NotReadYet
主要内容:
由于更新了光子重建的程序,导致伽马暴的LAT光子也要重新分析。
看来最可靠的LAT的结果得等他们的最终catalog了,鬼知道什么时候他们又重新reconstruction一把。
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文章信息:
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Title: | New Fermi-LAT Event Reconstruction Reveals More High-energy Gamma Rays from Gamma-Ray Bursts | |
Authors: | Atwood, W. B.; Baldini, L.; Bregeon, J.; Bruel, P.; Chekhtman, A.; Cohen-Tanugi, J.; Drlica-Wagner, A.; Granot, J.; Longo, F.; Omodei, N.; Pesce-Rollins, M.; Razzaque, S.; Rochester, L. S.; Sgrò, C.; Tinivella, M.; Usher, T. L.; Zimmer, S. | |
Affiliation: | AA(Santa
Cruz Institute for Particle Physics, Department of Physics and
Department of Astronomy and Astrophysics, University of California at
Santa Cruz, Santa Cruz, CA 95064, USA | |
Publication: | The Astrophysical Journal, Volume 774, Issue 1, article id. 76, | |
Publication Date: | 09/2013 | |
Origin: | IOP | |
Astronomy Keywords: | astroparticle physics, cosmology: observations, gamma rays: general, methods: data analysis | |
DOI: | 10.1088/0004-637X/774/1/76 | |
Bibliographic Code: | 2013ApJ...774...76A |
Bibtex entry for this abstract Preferred format for this abstract (see Preferences) |
Labels: 4.4 high energy