论文标题
可观察的真空能量在扩展的空间中有限
Observable vacuum energy is finite in expanding space
论文作者
论文摘要
在这项工作中，我认为在扩大空间中，只有这些量子模式有助于无法超越可观察体积的测得的真空能。由于所有量化场模式都有各种可观察的后果，因此，当重力范围将观察者局限于有限体积量化模式时，应限于可观察到的贴片以保持与重力保持一致。 在可观察到的弗里德曼 - 莱默特雷 - 罗伯逊步行者（FLRW）空间中，能量弹药张量的真空期望值可以表示为离散场模式上的总和。弗里德曼（Friedmann）的第一个方程式提供了直接的紫外线截止，仅允许总和中有有限数量的模式。有限体积充当红外调节器，无需正则化和重量化，真空能量密度的计算是可以处理的。 为了测试这个想法的有效性，我在FLRW背景上量化标量场，并计算其在以真空为主导的，保形，全息极限的真空能量密度。在此极限中，我表明量子真空能量密度与哈勃参数的平方缩放，均与重力保持一致。在此示例中，量子真空扩大了空间，而扩展空间的地平线将真空的能量密度限制为观察到的值。
In this work I reason that in expanding space only those quantum modes contribute to the measured vacuum energy that do not transcend the observable volume. Since all quantised field modes have various observable consequences, when a gravitational horizon causally confines an observer to a finite volume quantised modes should be restricted to the observable patch to remain consistent with gravity. Within the observable patch of Friedmann-Lemaitre-Robertson-Walker (FLRW) space the vacuum expectation value of the energy-momentum tensor can be expressed as a sum over discrete field modes. Friedmann's first equation provides a straightforward ultraviolet cut-off allowing only a finite number of modes in the sum. The finite volume acts as an infrared regulator and the calculation of the vacuum energy density is tractable without regularisation and renormalisation. To test the validity of this idea I quantise a scalar field on an FLRW background and calculate its vacuum energy density in the vacuum dominated, conformal, holographic limit. In this limit I show that the quantum vacuum energy density scales with the square of the Hubble parameter, consistently with gravity. In this example quantum vacuum expands space while the horizon of the expanding space limits the energy density of the vacuum to the observed value.
