Swampland Constraints on No-Boundary Quantum Cosmology

The Hartle-Hawking no-boundary proposal describes the quantum creation of the universe. To have a non-negligible probability to obtain a classical expanding universe, eternal inflation is required, which is severely constrained by Swampland conjectures such as the refined de Sitter conjecture and the distance conjecture. We discuss this issue in detail and demonstrate the incompatibility. We show that the dimensionless parameters in the refined de Sitter conjecture should be bounded from above by a positive power of the scalar potential to realize the classical expanding universe. In other words, the probability of the classical expanding universe is extremely small under the Swampland conjectures unless the parameters are much smaller than unity. If they are order unity, on the other hand, the saddle-point solution itself ceases to exist implying a genuinely quantum universe.Comment: 34 pages, 14 figures; published version, minor corrections in Appendi

Application of Imaging Technology to Humans

Recent development of imaging technology has been remarkable and has given great impact to life science research. Moreover, attempts to apply this novel technique to humans and practice it in clinical medicine have also started. Especially, some articles report the utility of imaging living tissues that do not require any labeling in recent years. This “non-labeling imaging” technique has a great potential in human application and clinical medicine practice. In this review, we describe the application of imaging technology to humans, mainly focusing on the diagnosis of cancer by non-labeling imaging with multiphoton excitation microscopy.The version of record of this article, first published in Make Life Visible, is available online at Publisher’s website: https://doi.org/https://doi.org/10.1007/978-981-13-7908-6_2

Inflationary α\alpha-Attractor Models with Singular Derivative of Potential

A generalization of inflationary $\alpha$-attractor models (``polynomial $\alpha$-attractor'') was recently proposed by Kallosh and Linde, in which the potential involves logarithmic functions of the inflaton so that the derivative of the potential but not potential itself has a singularity. We find that the models can lead to viable inflationary observables even without the pole in the kinetic term. Also, the generalization with a pole order other than two does not significantly change the functional form of the potential. This allows a systematic analysis of the predictions of this class of models. Our models predict larger spectral index $n_s$ and tensor-to-scalar ratio $r$ than in the polynomial $\alpha$-attractor: typically, $n_s$ around 0.97--0.98 and $r$ observable by LiteBIRD. Taking advantage of the relatively large $n_s$, we discuss the modification of the potential to produce primordial black holes as the whole dark matter and gravitational waves induced by curvature perturbations detectable by LISA and BBO/DECIGO, while keeping $n_s$ in agreement with the Planck/BICEP/Keck data.Comment: 25 pages, 9 figures, 1 table. Published version; references and table adde

Lateral Loading Tests in The Pit for a Large-Diameter Deep Pile

Although the ground supporting the foundation can be regarded as three-dimensional nonlinear continuous body, in design, grounds are modeled as linear elastic springs. However, in reality, grounds exhibit nonlinear load-displacement (ρ-δ) characteristics. In Specifications for Highway Bridges (Japan Road Association, 1994), ground reaction coefficient is defined as the secant slope of noticeable displacement and load intensity on ρ-δ curve corrected according to width of foundation. For the purpose of examining the scale effect of large-diameter pile, this paper presents a study on scale effect of lateral ground reaction coefficient based on results of lateral loading tests performed using large loading plate in the pit of a large-diameter deep pile

Simultaneous two cross-sectional measurements of NH3 concentration in bent pipe flow using CT-tunable diode laser absorption spectroscopy

Urea Selective Catalytic Reduction (urea SCR) system is widely used for diesel engine to reduce the emission of NOx by NH3 which is provided by a hydrolysis of urea water. Concentration distribution of NH3 in an exhaust pipe is an important factor for improvement of the SCR efficiency and prevention of NH3 slip and urea deposit. Therefore, it is necessary to measure two-dimensional (2D) concentration of NH3 in detail. The purpose of this study is to develop the real-time two cross-sectional measurements technology of NH3 concentration using the computed tomography-tunable diode laser absorption spectroscopy (CT-TDLAS). Theoretical NH3 concentration distribution which was reconstructed by CT agreed to CFD results and quadruple pipe’s results showed good resolution by 14th order reconstruction. Therefore, this method has enough resolution and accuracy for measuring the concentration distribution of NH3. And this method was employed in a bent pipe model demonstrated a urea SCR system. The experimental results of two cross-sectional 2D concentration of NH3 show differences of the concentration distribution of NH3 each cross-section and flow pattern like swirl flow. It was found that CT-TDLAS was an effective method to measure concentration distribution of NH3 and observe characteristics of flow. In addition, observing flow pattern enable to validate CFD results, and it helps to improve efficiency of after treatment system

Void-induced cross slip of screw dislocations in fcc copper

Pinning interaction between a screw dislocation and a void in fcc copper is investigated by means of molecular dynamics simulation. A screw dislocation bows out to undergo depinning on the original glide plane at low temperatures, where the behavior of the depinning stress is consistent with that obtained by a continuum model. If the temperature is higher than 300 K, the motion of a screw dislocation is no longer restricted to a single glide plane due to cross slip on the void surface. Several depinning mechanisms that involve multiple glide planes are found. In particular, a depinning mechanism that produces an intrinsic prismatic loop is found. We show that these complex depinning mechanisms significantly increase the depinning stress

Finite-temperature phase diagram of two-component bosons in a cubic optical lattice: Three-dimensional t-J model of hard-core bosons

We study the three-dimensional bosonic t-J model, i.e., the t-J model of "bosonic electrons", at finite temperatures. This model describes the $s={1 \over 2}$ Heisenberg spin model with the anisotropic exchange coupling $J_{\bot}=-\alpha J_z$ and doped {\it bosonic} holes, which is an effective system of the Bose-Hubbard model with strong repulsions. The bosonic "electron" operator $B_{r\sigma}$ at the site $r$ with a two-component (pseudo-)spin $\sigma (=1,2)$ is treated as a hard-core boson operator, and represented by a composite of two slave particles; a "spinon" described by a Schwinger boson (CP$^1$ boson) $z_{r\sigma}$ and a "holon" described by a hard-core-boson field $\phi_r$ as $B_{r\sigma}=\phi^\dag_r z_{r\sigma}$. By means of Monte Carlo simulations, we study its finite-temperature phase structure including the $\alpha$ dependence, the possible phenomena like appearance of checkerboard long-range order, super-counterflow, superfluid, and phase separation, etc. The obtained results may be taken as predictions about experiments of two-component cold bosonic atoms in the cubic optical lattice.Comment: 8 pages, 14 figures, Size of figures has been adjuste