The momentum analyticity of two-point correlators from perturbation theory and AdS/CFT

The momentum plane analyticity of two point function of a relativistic thermal field theory at zero chemical potential is explored. A general principle regarding the location of the singularities is extracted. In the case of the N=4 supersymmetric Yang-Mills theory at large $N_c$, a qualitative change in the nature of the singularity (branch points versus simple poles) from the weak coupling regime to the strong coupling regime is observed with the aid of the AdS/CFT correspondence.Comment: 18 pages, 3 figures, typos fixed, 1 figure update

Non-abelian gauge structure in neutrino mixing

We discuss the existence of a non-abelian gauge structure associated with flavor mixing. In the specific case of two flavor mixing of Dirac neutrino fields, we show that this reformulation allows to define flavor neutrino states which preserve the Poincar\'e structure. Phenomenological consequences of our analysis are explored.Comment: 13 pages, 2 figure

Gerasimov-Drell-Hearn Sum Rule and the Discrepancy between the New CLAS and SAPHIR Data

Contribution of the K^+\Lambda channel to the Gerasimov-Drell-Hearn (GDH) sum rule has been calculated by using the models that fit the recent SAPHIR or CLAS differential cross section data. It is shown that the two data sets yield quite different contributions. Contribution of this channel to the forward spin polarizability of the proton has been also calculated. It is also shown that the inclusion of the recent CLAS C_x and C_z data in the fitting data base does not significantly change the result of the present calculation. Results of the fit, however, reveal the role of the S_{11}(1650), P_{11}(1710), P_{13}(1720), and P_{13}(1900) resonances for the description of the C_x and C_z data. A brief discussion on the importance of these resonances is given. Measurements of the polarized total cross section \sigma_{TT'} by the CLAS, LEPS, and MAMI collaborations are expected to verify this finding.Comment: 15 pages, 8 figure

Dirac Equation with Spin Symmetry for the Modified P\"oschl-Teller Potential in DD-dimensions

We present solutions of the Dirac equation with spin symmetry for vector and scalar modified P\"oschl-Teller potential within framework of an approximation of the centrifugal term. The relativistic energy spectrum is obtained using the Nikiforov-Uvarov method and the two-component spinor wavefunctions are obtain are in terms of the Jacobi polynomials. It is found that there exist only positive-energy states for bound states under spin symmetry, and the energy levels increase with the dimension and the potential range parameter $\alpha$.Comment: 9 pages and 1tabl

Production Across the Nordics

In the uncertain and volatile market that companies are currently facing worldwide, researchers and engineers\ua0become a key link to\ua0strengthen the industry and universities\ua0in order to\ua0understand, communicate, and tackle\ua0current challenges. In the PhD course, International Production, the goal is to investigate what makes Sweden and Iceland booming industrial hubs\ua0driven by technology. Through the\ua0visits to different types of industries, such as fintech, medical, or automotive industry,\ua0we as researchers have gained a better understanding of the challenges they are currently facing. This report is a summary of our findings and observations.\ua0\ua0The participants have focused on the\ua0six challenge areas highlighted within the Produktion2030 graduate school and summarize their findings as:\ua0\ua0•Resource-efficient production:\ua0Data as a resource is becoming increasingly important for the majority of companies in the Nordics and the application of traditional resource management tools on data is a suggested area for future research. \ua0•Flexible production:To strengthen organizations by\ua0enabling\ua0production systems to be flexible to address\ua0market variations is a key\ua0challenge to consider in the manufacturing industry•Virtual production development:Digitalization level is distinct in each Nodic country with the reason that each country has its own digitalization transformation policy and different measures on digitalization level.\ua0•Humans in the production system:Humans are central in the production systems of the visited companies. Use of automation technology and AI to support humans in their work may become more common in the future.•Circular production systems and maintenance:Circular production systems require a complex approach through the whole value chain. Industry in the Nordics has started the adoption of a circularity approach.\ua0•Integrated product and production development:\ua0Integration of product and production development is a key business factor for the Nordic countries, and geographical proximity between the two departments can have a beneficial effect. \ua0We hope that this report provides more\ua0details\ua0regarding\ua0the success and current challenges of the Swedish and Icelandic enterprises

Estrogen modulates mesenchyme-epidermis interactions in the adult nipple

Maintenance of specialized epidermis requires signals from the underlying mesenchyme; however, the specific pathways involved remain to be identified. By recombining cells from the ventral skin of the K14-PTHrP transgenic mice [which overexpress parathyroid hormone-related protein (PTHrP) in their developing epidermis and mammary glands] with those from wild type, we show that transgenic stroma is sufficient to reprogram wild-type keratinocytes into nipple-like epidermis. To identify candidate nipple-specific signaling factors, we compared gene expression signatures of sorted Pdgfrα-positive ventral K14-PTHrP and wild-type fibroblasts, identifying differentially expressed transcripts that are involved in WNT, HGF, TGFβ, IGF, BMP, FGF and estrogen signaling. Considering that some of the growth factor pathways are targets for estrogen regulation, we examined the upstream role of this hormone in maintaining the nipple. Ablation of estrogen signaling through ovariectomy produced nipples with abnormally thin epidermis, and we identified TGFβ as a negatively regulated target of estrogen signaling. Estrogen treatment represses Tgfβ1 at the transcript and protein levels in K14-PTHrP fibroblasts in vitro, while ovariectomy increases Tgfb1 levels in K14-PTHrP ventral skin. Moreover, ectopic delivery of Tgfβ1 protein into nipple connective tissue reduced epidermal proliferation. Taken together, these results show that specialized nipple epidermis is maintained by estrogen-induced repression of TGFβ signaling in the local fibroblasts