The recent measurement of the Higgs boson mass implies a relatively slow rise of the standard model Higgs potential at large scales, and a possible second minimum at even larger scales. Consequently, the Higgs field may develop a large vacuum expectation value during inflation. The relaxation of the Higgs field from its large postinflationary value to the minimum of the effective potential represents an important stage in the evolution of the Universe. During this epoch, the time-dependent Higgs condensate can create an effective chemical potential for the lepton number, leading to a generation of the lepton asymmetry in the presence of some large right-handed Majorana neutrino masses. The electroweak sphalerons redistribute this asymmetry between leptons and baryons. This Higgs relaxation leptogenesis can explain the observed matter-antimatter asymmetry of the Universe even if the standard model is valid up to the scale of inflation, and any new physics is suppressed by that high scale.PACS numbers: 98.80. Cq, 11.30.Fs, 14.80.Bn The recent discovery of a Higgs boson with mass 125 GeV [1,2] implies that the Higgs potential is very shallow and may even develop a second minimum, assuming that the standard model is valid at high energy scales [3]. During cosmological inflation, the Higgs field may be trapped in a quasistable second minimum or, alternatively, may develop a stochastic distribution of vacuum expectation values due to the flatness of the potential [4][5][6]. In both scenarios, the Higgs field relaxes to its vacuum state after inflation via a coherent motion. In this Letter we explore this epoch of Higgs relaxation.We show that the observed matter-antimatter asymmetry could arise during this epoch. The Sakharov conditions [7], necessary for baryogenesis, are generically satisfied in the presence of the out-of-equilibrium Higgs condensate evolving with time [8,9] and the neutrino Majorana masses that violate the lepton number.The standard model Higgs boson has a tree-level po-where Φ is an SU(2) doublet. Using a gauge transformation, one can write the classical field as Φ = 1/ √ 2){e iθ φ, 0 , where φ(x) is real. Loop corrections substantially modify this potential at large values. We will include one-loop and finite temperature corrections to the Higgs potential, although twoloop effects may also be important near the metastability boundary [3]. For the experimentally preferred top and Higgs mass values, the φ 2 = v EW = 246 GeV minimum appears to be metastable [3], which entails a number of important ramifications [10]. However, a stable vacuum is still possible within the experimental uncertainties [3]. Furthermore, higher-dimensional operators can modify the potential at large vacuum expectation value (VEV) [? ] and make the vacuum stable. During inflation, a scalar field may develop a nonzero VEV φ 2 for more than one reason. We will consider two cosmological scenarios that lead to two types of initial conditions.Initial condition 1 (IC-1).-IC-1 occurs for the central values of measured Higgs an...

An epoch of Higgs relaxation may occur in the early universe during or immediately following postinflationary reheating. It has recently been pointed out that leptogenesis may occur in minimal extensions of the Standard Model during this epoch [1]. We analyse Higgs relaxation taking into account the effects of perturbative and non-perturbative decays of the Higgs condensate, and we present a detailed derivation of the relevant kinetic equations and of the relevant particle interaction cross sections. We identify the parameter space in which a sufficiently large asymmetry is generated.

Abstract:The significant optical and size benefits of using a curved focal surface for imaging systems have been well studied yet never brought to market for lack of a high-quality, massproducible, curved image sensor. In this work we demonstrate that commercial silicon CMOS image sensors can be thinned and formed into accurate, highly curved optical surfaces with undiminished functionality. Our key development is a pneumatic forming process that avoids rigid mechanical constraints and suppresses wrinkling instabilities. A combination of formingmold design, pressure membrane elastic properties, and controlled friction forces enables us to gradually contact the die at the corners and smoothly press the sensor into a spherical shape. Allowing the die to slide into the concave target shape enables a threefold increase in the spherical curvature over prior approaches having mechanical constraints that resist deformation, and create a high-stress, stretch-dominated state. Our process creates a bridge between the high precision and low-cost but planar CMOS process, and ideal non-planar component shapes such as spherical imagers for improved optical systems. We demonstrate these curved sensors in prototype cameras with custom lenses, measuring exceptional resolution of 3220 line-widths per picture height at an aperture of f/1.2 and nearly 100% relative illumination across the field. Though we use a 1/2.3" format image sensor in this report, we also show this process is generally compatible with many state of the art imaging sensor formats. By example, we report photogrammetry test data for an APS-C sized silicon die formed to a 30° subtended spherical angle. These gains in sharpness and relative illumination enable a new generation of ultra-high performance, manufacturable, digital imaging systems for scientific, industrial, and artistic use. References and links 1.S.B.Rim, P.B. Catrysse, R. Dinyari, K. Huang, P. Peumans, The optical advantages of curved focal plane arrays, Optics Express, 16 (7), 4965-4971 (2008 TRANSDUCERS 2015TRANSDUCERS , 7181365, 2073TRANSDUCERS -2076TRANSDUCERS (2015.

During inflation, scalar fields, including the Higgs boson, may acquire a nonzero vacuum expectation value, which must later relax to the equilibrium value during reheating. In the presence of the time-dependent condensate, the vacuum state can evolve into a state with a nonzero particle number. We show that, in the presence of lepton number violation in the neutrino sector, the particle production can explain the observed matter-antimatter asymmetry of the universe. We find that this form of leptogenesis is particularly effective when the Higgs condensate decays rapidly and at low reheat scale. As part of the calculation, we present some exact results for the Bogoliubov transformations for Majorana fermions with a nonzero time-dependent chemical potential, in addition to a time-dependent mass.

We study the observational constraints on the exponential gravity model of f (R) = −βR s (1 − e −R/Rs ). We use the latest observational data including Supernova Cosmology Project (SCP) Union2 compilation, Two-Degree Field Galaxy Redshift Survey (2dFGRS), Sloan Digital Sky Survey Data Release 7 (SDSS DR7) and Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP7) in our analysis. From these observations, we obtain a lower bound on the model parameter β at 1.27 (95% CL) but no appreciable upper bound. The constraint on the present matter density parameter is 0.245 < Ω 0 m < 0.311 (95% CL). We also find out the best-fit value of model parameters on several cases. PACS numbers: 98.80.-k, 04.50.Kd, 95.36.-x * louis.lineage@msa.hinet.net †