Experimental study of the unknown component of the vacuum energy

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K20921
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 15:Particle-, nuclear-, astro-physics, and related fields
• Research Institution: Osaka University
• Principal Investigator: Shima Tatsushi 大阪大学, 核物理研究センター, 准教授 (10222035)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: 真空の自己エネルギー / ダークエネルギー / 光半導体 / CdTe

Outline of Final Research Achievements

Self energy of quantum vacuum generates positive pressure independent of geometrical boundary condition of the space, and therefore it is suggested to be related to the cosmic dark energy. Since the self energy depends on the cutoff frequency (Fc) of the boundary, its effect is expected to be detected as the change of the pressure on the boundary according to Fc. Since the pressure should be very small, it is essential to change Fc and measure displacement of the boundary by pressure without contact. For that purpose we employed optical semiconductor (CdTe) as the material for the electrode of the boundary, and confirmed Fc can be controlled by changing the illuminance onto the electrode. For detection of the pressure onto the boundary, we developed the method of measuring displacement of the electrode as the change of its capacitance with the input RF signal. At present, the accuracy of the measurement is about 3%, which will be improved with longer measuring time of the RF signal.

Free Research Field

素粒子実験・原子核実験

Academic Significance and Societal Importance of the Research Achievements

真空の自己エネルギーは、宇宙背景放射の観測から推測されているダークエネルギーとの関連が示唆されており、その性質を調査することは基礎物理学における重要課題であるが、これまでは繰り込みの処理によって省かれ、より深い考察があまり為されていなかった。自己エネルギーは系の境界面の遮断周波数に依存すると考えられ、その性質を利用して実在が確かめられれば量子場の理論や宇宙論に対する大きなインパクトとなる。本研究では、自己エネルギーの検出に置いて鍵となる、非接触での遮断周波数の操作および圧力変化の検知方法について原理的妥当性が確認され、自己エネルギーの検出に向けての重要な足掛かりが得られた。