Particle physics implications of Wilkinson microwave anisotropy project measurements

We present an overview of the implications of the WMAP data for particle physics. The standard parameter set epsilon, eta and xi characterising the inflaton potential can be related to the power-law indices characterising deviation of the CMB spectrum from the scale invariant form. Different classes of inflation potentials are in turn naturally associated with different unified schemes. At present WMAP does not exclude any but a few simple unified models. In particular, hybrid models favoured by supersymmetric unification continue to be viable. However future improvement in data leading to better determination of the 'running' of power-law indices should help to narrow the possibilities for unified models. The main conclusion is that WMAP is consistent with the paradigm of GUT scale (10(16) GeV) inflation

Reconciling low multipole anomalies and reheating in single field inflationary models

Reheating phase of inflationary Universe can be modeled by parameters T-reh, (omega) over bar (reh) and N-reh, which can be constrained by the scalar spectral amplitude A(s) and the scalar spectral index n(s). On the other hand the low multipole anomalies in the CMB can be modeled by suitable features in the inflaton potential. We show that the parameters of these features in the inflaton potential provide additional constraints on the reheating parameters. For several single field models we find that the reheating parameters are substantially more constrained by the requirement of compatibility with the proposed explanation for low multipole anomalies

Cosmic strings at the electroweak phase-transition - an application

We consider the phase transition in the electroweak theory with two Higgs doublets in the presence of preexisting cosmic strings. The correction to the effective action coming from the triangle diagram consisting of one vector and two scalar legs is calculated. This correction biases the Chern-Simons number which in turn generates a baryon asymmetry which we estimate to be similar to 10(-10) - 10(-12)

Bubble wall dynamics, generalized yukawa couplings and adequate electroweak baryogenesis in two-Higgs-doublet model

Baryogenesis at the electroweak scale depends on bubble wall dynamics and particle physics. We trace the dynamics of the relative phase during bubble formation in two-Higgs-doublet model (2HDM) and compute its contribution to the mechanism proposed by McLerran-Shaposhnikov-Turok-Voloshin. This enhances the intrinsic contribution of the diagram and would mean overall enhancement if diffusion processes are taken into account. We also show that in 2HDM with less stringent constraints on Yukawa couplings than those imposed by natural flavor conservation, there are additional diagrams contributing to the effective chemical potential. These two effects can combine with several others to produce adequate asymmetry at the electroweak scale

Stability of false vacuum in supersymmetric theories with cosmic strings

We study the stability of supersymmetry breaking vacuum in the presence of cosmic strings arising in the messenger sector. For certain ranges of the couplings, the desired supersymmetry breaking vacua become unstable against decay into phenomenologically unacceptable vacua. This sets constraints on the range of allowed values of the coupling constants appearing in the models and more generally on the chosen dynamics of gauge symmetry breaking

Topological pseudodefects of a supersymmetric SO(10) model and cosmology

Obtaining realistic supersymmetry preserving vacua in the minimal renormalizable supersymmetric Spin(10) GUT model introduces considerations of the nontrivial topology of the vacuum manifold. The D-parity of low energy unification schemes gets lifted to a one-parameter subgroup U(1)(D) of Spin(10). Yet, the choice of the fields signaling spontaneous symmetry breaking leads to disconnected subsets in the vacuum manifold related by the D-parity. The resulting domain walls, existing due to topological reasons but not stable, are identified as topological pseudodefects. We obtain a class of one-parameter paths connecting D-parity flipped vacua and compute the energy barrier height along the same. We consider the various patterns of symmetry breaking which can result in either intermediate scale gauge groups or a supersymmetric extension of the standard model. If the onset of inflation is subsequent to grand unified theory (GUT) breaking, as could happen also if inflation is naturally explained by the same GUT, the existence of such pseudo-defects can leave signatures in the CMB. Specifically, this could have an impact on the scale invariance of the CMB fluctuations and Large Scale Structure data at the largest scale