Effect of time variation in the Higgs vacuum expectation value on the cosmic microwave background - art. no. 023510

A time variation in the Higgs vacuum expectation value alters the electron mass and thereby changes the ionization history of the universe. This chang e produces a measurable imprint on the pattern of cosmic microwave backgrou nd (CMB) fluctuations. The nuclear masses and nuclear binding energies, as well as the Fermi coupling constant, are also altered, with negligible impa ct on the CMB. We calculate the changes in the spectrum of the CMB fluctuat ions as a function of the change in the electron mass m(e). We find that fu ture CMB experiments could be sensitive to \Delta m(e)/m(e)\similar to \Del ta G(F)/G(F)\similar to 10(-2)-10(-3). However, we also show that a change in m(e) is nearly, but not exactly, degenerate with a change in the fine-st ructure constant alpha. If both m(e) and alpha are time varying, the corres ponding CMB limits are much weaker, particularly for l < 1000.