**126**, 05014 (2016)

https://doi.org/10.1051/epjconf/201612605014

## False vacuum as an unstable state

University of Zielona Góra, Institute of Physics, ul. Prof. Z. Szafrana 4a, 65–516 Zielona Góra, Poland

^{a} e-mail: K.Urbanowski@if.uz.zgora.pl; k.a.urbanowski@gmail.com

Published online: 4 November 2016

Calculations performed within the Standard Model suggest that the electroweak vacuum is unstable if *M _{H}* < 126 GeV, (

*M*is the mass of the Higgs particle). LHC discovery of the Higgs boson indicates that

_{H}*M*≃ 125 GeV. So the vacuum in our Universe may be unstable. We analyze properties of unstable vacuum states from the point of view of the quantum theory. At asymptotically late times the survival probability as a function of time t has an inverse power–like form. We show that at this time region the energy of the false vacuum states tends to the energy of the true vacuum state as 1/

_{H}*t*

^{2}for

*t*→ ∞. This means that the energy density in the unstable vacuum state should have analogous properties and hence the cosmological constant Λ = Λ(

*t*) too. So Λ in the Universe with the unstable vacuum should have a form of the sum of the “bare” cosmological constant and of the term of a type , (where Λ

^{bare}is the cosmological constant for the Universe with the true vacuum).

*© The Authors, published by EDP Sciences, 2016*

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