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arXiv 2012.14301hep-thquant-ph
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再论闭分段一致弦

The closed piecewise uniform string revisited

M. Bordag, I. G. Pirozhenko

摘要:

我们重新考虑了{30年前}为研究真空能而引入的复合弦模型。该模型由一个标量场组成,描述了由具有不同张力和质量密度的分段恒定部分组成的弦的横向振动,保持光速恒定穿过结。我们考虑的频谱使用转移矩阵和切比雪夫多项式得到一个封闭的公式的本征频率。我们计算真空和自由能以及熵的这个系统在两种方法,一个使用轮廓积分和另一个使用赫维茨zeta函数。后者的结果在一个代表性的有限总和多项式。几种极限情况下,被认为是以及,例如,高温膨胀,这是表示在热核系数。真空能量没有紫外发散,由于光速恒定,相应的热核系数$a_1$为零。这与宏观电动力学中具有等折射边界条件的类似情况是平行的。

英文摘要:

We reconsider the composite string model introduced {30 years ago} to study the vacuum energy. The model consists of a scalar field, describing the transversal vibrations of a string consisting of piecewise constant sections with different tensions and mass densities, keeping the speed of light constant across the junctions. We consider the spectrum using transfer matrices and Chebyshev polynomials to get a closed formula for the eigenfrequencies. We calculate vacuum and free energy as well as the entropy of this system in two approaches, one using contour integration and another one using a Hurwitz zeta function. The latter results in a representation in terms of finite sums over polynomials. Several limiting cases are considered as well, for instance, the high-temperature expansion, which is expressed in terms of the heat kernel coefficients. The vacuum energy has no ultraviolet divergences, and the corresponding heat kernel coefficient $a_1$ is zero due to the constancy of the speed of light. This is in parallel to a similar situation in macroscopic electrodynamics with isorefractive boundary conditions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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