119206528
Large primordial trispectra in general single field inflation
We compute the large scalar four-point correlation functions in general single field inflation models, where the inflaton Lagrangian is an arbitrary function of the inflaton and its first derivative. We find that the leading order trispectra have four different shapes determined by three parameters. We study features in these shapes that can be used to distinguish among themselves, and between them and the trispectra of the local form. For the purpose of data analyses, we give two simple representative forms for these "equilateral trispectra". We also study the effects on the trispectra if the initial state of inflation deviates from the standard Bunch-Davies vacuum.
118533325
Quasi-Single Field Inflation and Non-Gaussianities
In quasi-single field inflation models, massive isocurvature modes, that are coupled to the inflaton and have mass of order the Hubble parameter, can have nontrivial impacts on density perturbations, especially non-Gaussianities. We study a simple example of quasi-single field inflation in terms of turning inflaton trajectory. Large bispectra with a one-parameter family of novel shapes arise, lying between the well-known local and equilateral shape. The trispectra can also be very large and its magnitude tNL can be much larger than fNL2.
2921220
Non-Gaussianity, isocurvature perturbation, gravitational waves, and a no-go theorem for the isocurvaton
We investigate the isocurvaton model, in which the isocurvature perturbation plays a role in suppressing the curvature perturbation, and large non-Gaussianity and gravitational waves can be produced with no isocurvature perturbation for dark matter. We show that in the slow-roll noninteracting multifield theory, the isocurvaton mechanism cannot be realized. This result can also be generalized to most of the studied models with generalized kinetic terms. We also study the implications for the curvaton model. We show that there is a combined constraint for curvaton on non-Gaussianity, gravitational waves, and isocurvature perturbation. The technique used in this paper can also help to simplify some calculations in the mixed inflaton and curvaton models. We also investigate the possibility of producing large negative non-Gaussianity and nonlocal non-Gaussianity in the curvaton model.
17457342
Curvaton dynamics and the non-linearity parameters in the curvaton model
We investigate the curvaton dynamics and the non-linearity parameters in the curvaton model with a potential slightly deviating from the quadratic form in detail. The non-linearity parameter gNL will show up due to the curvaton self-interaction. We also point out that the leading order of the non-quadratic term in the curvaton potential can be negative, for example in the axion-type curvaton model. If a large positive gNL is detected, the axion-type curvaton model will be preferred.
119270914
Quadra-Spectrum and Quint-Spectrum from Inflation and Curvaton Models
We calculate the quadra-spectrum and quint-spectrum, corresponding to five and six point correlation functions of the curvature perturbation. For single field inflation with standard kinetic term, the quadra-spectrum and quint-spectrum are small, which are suppressed by slow roll parameters. The calculation can be generalized to multiple fields. When there is no entropy perturbation, the quadra-spectrum and quint-spectrum are suppressed as well. With the presence of entropy perturbation, the quadra-spectrum and quint-spectrum can get boosted. We illustrate this boost in the multi-brid inflation model. For the curvaton scenario, the quadra-spectrum and quint-spectrum are also large in the small r limit. We also calculate representative terms of quadra-spectrum and quint-spectrum for inflation with generalized kinetic terms, and estimate their order of magnitude for quasi-single field inflation.
119112752
CMB statistical anisotropies of classical and quantum origins
We examine the impact of different anisotropic relics on inflation, in particular the predictions on the density perturbations. These relics can be the source of the large scale anomalies in the cosmic microwave background. There are two different types of background relics, one from the matter sector and the other purely from the metric. Although the angular-dependence of the statistical anisotropy in both cases are degenerate, the scale-dependence are observationally distinctive. In addition, we demonstrate that non-Bunch-Davies vacuum states can extend the statistical anisotropy to much shorter scales, and leave a scale-dependence that is insensitive to the different backgrounds but sensitive to the initial quantum state.
24870149
Impedance Database II for the Advanced Photon Source storage ring
The first impedance database constructed at the advanced photon source was successfully used in reproducing the main characteristics of single-bunch instabilities observed in the storage ring. However, the finite bandwidth of the corresponding impedance model was limited to 40 GHz, which happens to be the resolution limit of the density modulation observed in the microwave instability simulation. In order to resolve simulation results never verified in the experiments, we decided to extend the calculated bandwidth of impedance to 100-200 GHz by recalculating the wake potentials excited by a shorter bunch. Since low-order electromagnetic code requires 20-40 grid points per wavelength, reducing the bunch length required a large number of grids for the 3D structure. We used bunch lengths of 1- and 2-mm in the Gaussian distribution in the impedance database II project. For the large-scale computation we used the 3D electromagnetic code GdfidL for wake potential calculation at the cluster equipped with 240 GB of memory. The resultant wake potential excited by the short bunch together with application to the storage ring for collective effects is presented in this paper.
36793805
False vacuum decay in Jordan-Brans-Dicke cosmologies
Abstract We examine the bubble nucleation rate in a first-order phase transition taking place in a background Jordan-Brans-Dicke cosmology. We compute the leading order terms in the nucleation rate when the Jordan-Brans-Dicke field is large (i.e., late times) by means of a Weyl rescaling of the fields in the theory. We find that despite the fact that the Jordan-Brans-Dicke field (hence the effective gravitational constant) has a time dependence in the false vacuum, at late times the nucleation rate is time independent.
182183518
Neutral hadron production at LEP with the L3 detector
15016676
A low temperature expansion for matrix quantum mechanics
A bstractWe analyze solutions to loop-truncated Schwinger-Dyson equations in massless N=2$$ \mathcal{N}=2 $$ and N=4$$ \mathcal{N}=4 $$ Wess-Zumino matrix quantum mechanics at finite temperature, where conventional perturbation theory breaks down due to IR divergences. We find a rather intricate low temperature expansion that involves fractional power scaling in the temperature, based on a consistent “soft collinear” approximation. We conjecture that at least in the N=4$$ \mathcal{N}=4 $$ matrix quantum mechanics, such scaling behavior holds to all perturbative orders in the 1/N expansion. We discuss some preliminary results in analyzing the gauged supersymmetric quantum mechanics using Schwinger-Dyson equations, and comment on the connection to metastable microstates of black holes in the holographic dual of BFSS matrix quantum mechanics.
119291530
Quantum Wave Equation of Photon
In this paper, we give the quantum wave equations of single photon when it is in the vacuum and medium. With these wave equations, we can study light interference and diffraction with the approach of quantum theory, and also can study the quantum property of photon when it is in a general crystal and photonic crystal. Otherwise, it can be applied in quantum optics and condensed matter feld.