APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Hassan Firouzjahi (Institute for Research in Fundamental Sciences)
Title: Cosmological constant problem on the horizon
Date (JST): Mon, Mar 07, 2022, 15:00 - 16:00
Place: Zoom
Related File: 2776.pdf
Abstract: We revisit the quantum cosmological constant problem and highlight the important roles played by the dS horizon of zero point energy. We argue that fields which are light enough to have dS horizon of zero point energy comparable to the FLRW Hubble radius are the main contributor to dark energy. On the other hand, the zero point energy of heavy fields develop nonlinearities on sub-Hubble scales and can not contribute to dark energy. Our proposal provides a simple resolution for both the old and new cosmological constant problems by noting that there exists a field, the (lightest) neutrino, which happens to have a mass comparable to the present background photon temperature. The natures of dark energy and dark matter are unified in this proposal in which the zero point energy of light fields are the source of dark energy while dark matter is sourced by the zero point energy of heavy fields.