Signatures of very high energy physics in the squeezed limit of the bispectrum (violation of Maldacena's condition)

We investigate the signatures in the squeezed limit of the primordial scalar bispectrum due to modifications of the standard theory at high energy. In particular, we consider the cases of modified dispersion relations and/or modified initial quantum state (both in the Boundary Effective Field Theory and in the New Physics Hyper-Surface formulations). Using the in-in formalism we study in details the squeezed limit of the contributions to the bispectrum from all possible cubic couplings in the effective theory of single-field inflation. We find general features such as enhancements and/or non-local shape of the non-Gaussianities, which are relevant, for example, for measurements of the halo bias and which distinguish these scenarios from the standard one (with Bunch-Davies vacuum as initial state and standard kinetic terms). We find that the signatures change according to the magnitude of the scale of new physics, and therefore several pieces of information regarding high energy physics could be obtained in case of detection of these signals, especially bounds on the scales of new physics.Comment: 37 pages plus bibliography, version matching the one accepted for publication by JCAP. Increased pedagogical comments, improved presentation and text, added reference

Optical autocollimator for vibration measurements at Diamond I13 beamline

I13 is a 250 m long hard X ray beamline for imaging and coherence experiments at the Diamond Light Source. The beamline comprises two independent experimental branches one for imaging in direct space using X ray microscopy and one for imaging in reciprocal space using coherent imaging techniques. The mechanical stability is very important for implementation of increased capabilities at latest generation of long beamlines. Therefore, the beam stability monitoring is essential part of the day to day operation of the beamlines as well as for analysis of mechanical instability sources for the Diamond II upgrade. In this paper we present the setup developed to measure mechanical stability of beamline based on optical autocollimato

Micro- and nano-imaging at the diamond beamline I13L-imaging and coherence

The Diamond Beamline I13L is dedicated to imaging on the micron- and nano-lengthscale, operating in the energy range between 6 and 30 keV. For this purpose two independent stations have been built. The imaging branch is fully operational for micro-tomography and in-line phase contrast imaging with micrometer resolution. Currently a full-field microscope providing 50nm spatial resolution over a field of view of 100 μm is being tested. On the coherence branch, coherent diffraction imaging techniques such as ptychography and coherent X-ray Bragg diffraction are currently developed. The beamline contains a number of unique features. The machine layout has been modified to the so-called mini-beta scheme, providing significantly increased flux from the two canted undulators. New instrumental designs such as a robot arm for the detector in diffraction experiments have been employed. The imaging branch is operated in collaboration with Manchester University, called therefore the Diamond-Manchester Branchline.</p

The viral chemokine MCK-2 of murine cytomegalovirus promotes infection as part of a gH/gL/MCK-2 complex.

Human cytomegalovirus (HCMV) forms two gH/gL glycoprotein complexes, gH/gL/gO and gH/gL/pUL(128,130,131A), which determine the tropism, the entry pathways and the mode of spread of the virus. For murine cytomegalovirus (MCMV), which serves as a model for HCMV, a gH/gL/gO complex functionally homologous to the HCMV gH/gL/gO complex has been described. Knock-out of MCMV gO does impair, but not abolish, virus spread indicating that also MCMV might form an alternative gH/gL complex. Here, we show that the MCMV CC chemokine MCK-2 forms a complex with the glycoprotein gH, a complex which is incorporated into the virion. We could additionally show that mutants lacking both, gO and MCK-2 are not able to produce infectious virus. Trans-complementation of these double mutants with either gO or MCK-2 showed that both proteins can promote infection of host cells, although through different entry pathways. MCK-2 has been extensively studied in vivo by others. It has been shown to be involved in attracting cells for virus dissemination and in regulating antiviral host responses. We now show that MCK-2, by forming a complex with gH, strongly promotes infection of macrophages in vitro and in vivo. Thus, MCK-2 may play a dual role in MCMV infection, as a chemokine regulating the host response and attracting specific target cells and as part of a glycoprotein complex promoting entry into cells crucial for virus dissemination