3 research outputs found
A New Approach to Flatness, Horizon and Late-time Accelerating Expansion Problems on the basis of Mach Principle
Based on the idea that the components of a cosmological metric may be
determined by the total gravitational potential of the universe, the scalar
field {\phi} = 1/G in the Jordan-Brans-Dicke (JBD) theory is introduced as
evolving with the inverse square of the scale factor. Since the gravitational
potential is related to the field {\phi} resulting from Mach principle and
depends on time due to the expansion of space, this temporal evolution of the
field should be in accord with the evolution of time and space intervals in the
metric tensor. For the same reason, the time dependence of the field makes
these comoving intervals relative for different points on the time axis. Thus,
it has been shown that introduction of the cosmic gravitational potential as a
time dependent scalar field which decreases with 1/a2 in the
coordinate-transformed Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime,
may resolve flatness, horizon and late-time accelerating expansion problems in
the standard model of cosmology. The luminosity distance vs redshift data of
Type Ia supernovae is in agreement with this approach.Comment: 7 page
The Higgs field and the Jordan Brans Dicke cosmology
We investigate a field theoretical approach to the Jordan–Brans–Dicke (JBD) theory extended with a particular potential term on a cosmological background by starting with the motivation that the Higgs field and the scale factor of the universe are related. Based on this relation, it is possible to come up with mathematically equivalent but two different interpretations. From one point of view while the universe is static, the masses of the elementary particles change with time. The other one, which we stick with throughout the manuscript, is that while the universe is expanding, particle masses are constant. Thus, a coupled Lagrangian density of the JBD field and the scale factor (the Higgs field), which exhibit a massive particle and a linearly expanding space in zeroth order respectively, is obtained. By performing a coordinate transformation in the field space for the reduced JBD action whose kinetic part is nonlinear sigma model, the Lagrangian of two scalar fields can be written as uncoupled for the Higgs mechanism. After this transformation, as a result of spontaneous symmetry breaking, the time dependent vacuum expectation value (vev) of the Higgs field and the Higgs bosons which are the particles corresponding to quantized oscillation modes about the vacuum, are found