dirac 物理里的所有积分至少都是Lebque积分你将坐标空间 ...
phymath999.blogspot.com/.../dirac-lebque-cutoff-delt...
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1 day ago - 你将坐标空间有限化就意味着, 你在动量空间加上了红外cutoff, 动量空间 ..... 这个式子物理上至少有意义, 你考虑一个波函数为delta函数在不同位置 ...
In physics, an infrared divergence or infrared catastrophe is a situation in which an integral, for example a Feynman diagram, diverges because of contributions of objects with very small energy approaching zero, or, equivalently, because of physical phenomena at very long distances.
The infrared (IR) divergence only appears in theories with massless particles (such as photons). They represent a legitimate effect that a complete theory often implies. One way to deal with it is to impose an infrared cutoff and take the limit as the cutoff approaches zero and/or refine the question. Another way is to assign the massless particle a fictitious mass, and then take the limit as the fictitious mass vanishes.
The divergence is usually in terms of particle number and not empirically troubling, in that all measurable quantities remain finite.[1][2] (Unlike in the case of the UV catastrophe where the energies involved diverge.)
The infrared (IR) divergence only appears in theories with massless particles (such as photons). They represent a legitimate effect that a complete theory often implies. One way to deal with it is to impose an infrared cutoff and take the limit as the cutoff approaches zero and/or refine the question. Another way is to assign the massless particle a fictitious mass, and then take the limit as the fictitious mass vanishes.
The divergence is usually in terms of particle number and not empirically troubling, in that all measurable quantities remain finite.[1][2] (Unlike in the case of the UV catastrophe where the energies involved diverge.)
20楼. 因为探测器不能探测任意低能的光子，所以红外发散端仍旧是个unobservable，可以引入cutoff
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... 它可能标度不变，在这种情况下，由于红外发散，严格点说S矩阵元不是一个良好定义的量。 ... 此外，在凝聚态理论中，系统的红外固定点理论描写了各种临界现象。 ..... 人们只需要考虑相涨落，长程上体系由一个自由场论描写，两点相之间(或 .... P.C. Hohenberg: “Existence of Long-Range Order in One and Two Dimensions”, Phys
物理| 生命在于发现
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delta波函数 - 豆瓣
www.douban.com/group/topic/22854186/
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Investigations of photoresponse signals of LT-GaAs ... - OALib
www.oalib.com/paper/2065548
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Bo Zhang's Homepage » 宇宙红外背景辐射与高能光子
bzhang.lamost.org/website/.../ir_background_interacti...
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维数正规化是不是和分数维有关系？ - 百度贴吧
c.tieba.baidu.com/p/746341178?lp=5028&mo...1
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CN101221995A - Google
www.google.com/patents/CN101221995A?cl=en - Translate this page
我对重整化等的一点小小的想法 - 繁星客栈- 观星楼(自然科学 ...
www.changhai.org/bbs/load_article.php?fid=3&aid...
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Apr 10, 2005 - 29 posts - 6 authors
红外发散远没有那么严重，所以这里就不必提。 .... A physical cut-off will be, as we probe higher energy (therrefore smallar size) .... 把东西从动量空间傅立叶变换回去就清楚了：如果截断不趋于无穷，你将不能得到delta function。繁星客栈- 网友原创作品集
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