The second law of thermodynamics under unitary evolution and external operations

The von Neumann entropy cannot represent the thermodynamic entropy of equilibrium pure states in isolated quantum systems. The diagonal entropy, which is the Shannon entropy in the energy eigenbasis at each instant of time, is a natural generalization of the von Neumann entropy and applicable to equilibrium pure states. We show that the diagonal entropy is consistent with the second law of thermodynamics upon arbitrary external unitary operations. In terms of the diagonal entropy, thermodynamic irreversibility follows from the facts that quantum trajectories under unitary evolution are restricted by the Hamiltonian dynamics and that the external operation is performed without reference to the microscopic state of the system.Fruitful discussions with Masahiro Hotta, Takashi Mori, Takahiro Sagawa, and Takanori Sugiyama are gratefully acknowledged. This work was supported by KAKENHI 26287088, a Grant-in-Aid for Scientific Research on Innovation Areas "Topological Quantum Phenomena" (KAKENHI 22103005), and the Photon Frontier Network Program, from MEXT of Japan. T.N.I. acknowledges the JSPS for financial support (Grant No. 248408). N.S. was supported by a Grant-in-Aid for JSPS Fellows (Grant No. 250588). (26287088 - KAKENHI; 22103005 - KAKENHI; Photon Frontier Network Program, from MEXT of Japan; 24840 - JSPS; 250588)Accepted manuscrip

Criteria of off-diagonal long-range order in Bose and Fermi systems based on the Lee-Yang cluster expansion method

The quantum-statistical cluster expansion method of Lee and Yang is extended to investigate off-diagonal long-range order (ODLRO) in one- and multi-component mixtures of bosons or fermions. Our formulation is applicable to both a uniform system and a trapped system without local-density approximation and allows systematic expansions of one- and multi-particle reduced density matrices in terms of cluster functions which are defined for the same system with Boltzmann statistics. Each term in this expansion can be associated with a Lee-Yang graph. We elucidate a physical meaning of each Lee-Yang graph; in particular, for a mixture of ultracold atoms and bound dimers, an infinite sum of the ladder-type Lee-Yang 0-graphs is shown to lead to Bose-Einstein condensation of dimers below the critical temperature. In the case of Bose statistics, an infinite series of Lee-Yang 1-graphs is shown to converge and gives the criteria of ODLRO at the one-particle level. Applications to a dilute Bose system of hard spheres are also made. In the case of Fermi statistics, an infinite series of Lee-Yang 2-graphs is shown to converge and gives the criteria of ODLRO at the two-particle level. Applications to a two-component Fermi gas in the tightly bound limit are also made.Comment: 21 pages, 10 figure

Design and performance of a F/#-conversion microlens for Prime Focus Spectrograph at Subaru Telescope

The PFS is a multi-object spectrograph fed by 2394 fibers at the prime focus of Subaru telescope. Since the F/# at the prime focus is too fast for the spectrograph, we designed a small concave-plano negative lens to be attached to the tip of each fiber that converts the telescope beam (F/2.2) to F/2.8. We optimized the lens to maximize the number of rays that can be confined inside F/2.8 while maintaining a 1.28 magnification. The microlenses are manufactured by glass molding, and an ultra-broadband AR coating (<1.5% for lambda=0.38-1.26 um) will be applied to the front surface.Comment: 7 pages, 8 figures, SPIE201

Supermassive Black Hole Mass Functions at Intermediate Redshifts from Spheroid and AGN Luminosity Functions

Redshift evolution of supermassive black hole mass functions (BHMFs) is investigated up to z ~ 1. BHMFs at intermediate redshifts are calculated in two ways. One way is from early-type galaxy luminosity functions (LFs); we assume an M_BH - L_sph correlation at a redshift by considering a passive evolution of L_sph in the local relationship. The resultant BHMFs (spheroid-BHMFs) from LFs of red sequence galaxies indicates a slight decrease of number density with increasing redshift at M_BH > 10^{7.5-8} M_solar. Since a redshift evolution in slope and zeropoint of the M_BH - L_sph relation is unlikely to be capable of making such an evolution in BHMF, the evolution of the spheroid-BHMFs is perhaps due mainly to the decreasing normalization in the galaxy LFs. We also investigate how spheroid-BHMFs are affected by uncertainties existing in the derivation in detail. The other way of deriving a BHMF is based on the continuity equation for number density of SMBHs and LFs of active galactic nucleus (AGN). The resultant BHMFs (AGN-BHMFs) show no clear evolution out to z = 1 at M_BH > 10^8 M_solar, but exhibit a significant decrease with redshift in the lower mass range. Comparison of the spheroid-BHMFs with the AGN-BHMFs suggests that at M_BH > 10^{8} M_solar, the spheroid-BHMFs are broadly consistent with the AGN-BHMFs out to z ~ 1. The agreement between the spheroid-BHMFs and the AGN-BHMFs appears to support that most of the SMBHs are already hosted by massive spheroids at z ~ 1 and they evolve without significant mass growth since then.Comment: 13 pages, accepted for publication in MNRA

Prediction of carotid artery in-stentrestenosis by quantitative assessment ofvulnerable plaque using computed tomography

Background and purpose To assess the relationship between plaque volume evaluated by multidetector computed tomographic angiography (MDCT) and in-stent restenosis (ISR) after carotid artery stenting (CAS). Materials and methods From a retrospectively maintained database, data were collected for 52 patients with carotid artery stenosis treated with CAS between 2007 and 2012. We defined ISR of ≥ 50% as a peak systolic velocity ≥ 200 cm/s on echo-duplex scan. Carotid plaques were subdivided into four components according to radiodensity in Hounsfield units (HU) as follows: 600 HU. Risk factors that influenced ISR were compared using univariate and multivariate Cox regression analyses. Results During a median follow-up period of 36 months, ISR of ≥ 50% was detected in five patients (9.6%). In the univariate Cox proportional hazard regression analysis, renal insufficiency, coronary artery disease, total plaque volume, and plaque volumes with radiodensities < 0 and ≥ 600 HU increased the risk for ISR (P < 0.10). When the significant risk factors determined from the univariate analysis were subjected to a multivariate analysis, only the volumes of the plaque components with radiodensities < 0 HU independently predicted the development of ISR (hazard ratio: 1.041; 95% confidence interval: 1.006–1.078; P = 0.021). Conclusion Our data suggest that the high volume of the plaque components with radiodensities < 0 HU was independently associated with the increased risk of ISR after CAS. Quantitative and qualitative tissue characterizations of carotid plaques using MDCT might be a useful predictive tool of the development of ISR.Embargo Period 12 month

Induction of Chromatin Damage and Distribution of Isochromatid Breaks in Human Fibroblast Cells Exposed to Heavy Ions

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Long-term predictive factors of the morphology based outcome in bare platinum coiled intracranial aneurysms: Evaluation by pre- and post-contrast 3D time-of-flight MR angiography

Purpose Our aim was to identify long-term predictive factors of the morphology-based outcome (MBO) of bare platinum coiled intracranial aneurysms. Materials and Methods A retrospective analysis of 96 bare platinum coiled intracranial aneurysms followed up from 1997 to 2016 using pre- and post-contrast 3D time-of-flight MR angiography (MRA) was performed. Logistic regression analysis was used to identify factors associated with a positive history of surrounding coil mass enhancement (SCME) and poor MBO. Spearman's rank correlation test was used to analyze the relationship between the initial angiographic result (IAR) class, sequential change of the SCME category, and MBO grade. Results Factors independently associated with poor MBO were incomplete IAR (OR=14.94, 95%CI: 2.46, 289.21, P=0.002) and a history of SCME (OR=4.13, 95% CI: 1.05, 18.65, P=0.043). The MBO grade strongly correlated with the IAR class (correlation coefficient [r]=0.84, P&lt;0.0001). MBO grade correlated with sequential change of the SCME category (r=0.56, P&lt;0.0001). The sequential change of the SCME category correlated with IAR class (r=0.53, P&lt;0.0001). Conclusion Although IAR and its class were strong long-term predictive factors of MBO, a history of SCME and upgrading of sequential change of SCME category were also long-term predictive factors of the MBO of bare platinum coiled intracranial aneurysms