Ambiguity of black hole entropy in loop quantum gravity

We reexmine some proposals of black hole entropy in loop quantum gravity (LQG) and consider a new possible choice of the Immirzi parameter which has not been pointed out so far. We also discuss that a new idea is inevitable if we regard the relation between the area spectrum in LQG and that in the quasinormal mode analysis seriously.Comment: 4 pages, 1 figure, error corrected, PRD published versio

Searching for scalar boson decaying into light Z′Z' boson at collider experiments in U(1)Lμ−LτU(1)_{L_\mu-L_\tau} model

We study a model with $U(1)_{L_\mu - L_\tau}$ gauge symmetry and discuss collider searches for a scalar boson, which breaks $U(1)_{L_\mu - L_\tau}$ symmetry spontaneously, decaying into light $Z'$ gauge boson. In this model, the new gauge boson, $Z'$, with a mass lighter than $\mathcal{O}(100)$ MeV, plays a role in explaining the anomalous magnetic moment of muon via one-loop contribution. For the gauge boson to have such a low mass, the scalar boson, $\phi$ with $\mathcal{O}(100)$ GeV mass appears associated with the symmetry breaking. We investigate experimental constraints on $U(1)_{L_\mu - L_\tau}$ gauge coupling, kinetic mixing, and mixing between the SM Higgs and $\phi$. Then collider search is discussed considering $\phi$ production followed by decay process $\phi \to Z' Z'$ at the large hadron collider and the international linear collider. We also estimate discovery significance at the linear collider taking into account relevant kinematical cut effects.Comment: 28 pages, 9 figures, 5 tables: published versio

The universal area spectrum in single-horizon black holes

We investigate highly damped quasinormal mode of single-horizon black holes motivated by its relation to the loop quantum gravity. Using the WKB approximation, we show that the real part of the frequency approaches the value $T_{\rm H}\ln 3$ for dilatonic black hole as conjectured by Medved et al. and Padmanabhan. It is surprising since the area specrtum of the black hole determined by the Bohr's correspondence principle completely agrees with that of Schwarzschild black hole for any values of the electromagnetic charge or the dilaton coupling. We discuss its generality for single-horizon black holes and the meaning in the loop quantum gravity.Comment: 5 pages, 1 figure, references and comments adde

Charmonium at finite temperature in quenched lattice QCD

We study charmonium correlators in pseudoscalar and vector channels at finite temperature using lattice QCD simulation in the quenched approximation. Anisotropic lattices are used in order to have sufficient numbers of degrees of freedom in the Euclidean temporal direction. We focus on the low energy structure of the spectral function, corresponding to the ground state in the hadron phase, by applying the smearing technique to enhance the contribution to the correlator from this region. We employ two analysis procedures: the maximum entropy method (MEM) for the extraction of the spectral function without assuming a specific form, to estimate the shape of the spectral function, and the standard $\chi^2$ fit analysis using typical forms in accordance with the result of MEM, for a more quantitative evaluation. To verify the applicability of the procedures, we first analyze the smeared correlators as well as the point correlators at zero temperature. We find that by shortening the $t$-interval used for the analysis (a situation inevitable at $T>0$) the reliability of MEM for point correlators is lost, while it subsists for smeared correlators. Then the smeared correlators at $T\simeq 0.9 T_c$ and $1.1 T_c$ are analyzed. At $T\simeq 0.9 T_c$, the spectral function exhibits a strong peak, well approximated by a delta function corresponding to the ground state with almost the same mass as at T=0. At $T\simeq 1.1 T_c$, we find that the strong peak structure still persists at almost the same place as below $T_c$, but with a finite width of a few hundred MeV. This result indicates that the correlators possess a nontrivial structure even in the deconfined phase.Comment: 19 pages, 26 figure

Numerical study of staggered quark action on quenched anisotropic lattices

The staggered quark action on anisotropic lattices is studied. We carry out numerical simulations in the quenched approximation at three values of lattice spacing ($a_{\sigma}^{-1}=1-2$ GeV) with the anisotropy $\xi= a_{\sigma}/a_{\tau}=4$, where $a_{\sigma}$ and $a_{\tau}$ are the spatial and temporal lattice spacings, respectively. The bare anisotropy $\gamma_F$ in the quark action is numerically tuned through the ratio of meson masses in the fine and coarse directions, and through the dispersion relation of a meson, so that the renormalized fermionic anisotropy coincides with that of the gauge field. The discrepancy between these two calibration schemes provides an estimate of the finite lattice artifact, which is found to be sizable in the range of cutoff explored in this work. We also compute the meson masses using correlators with the wall source at the tuned anisotropy parameter. The flavor symmetry breaking effect smoothly decreases as $\beta$ increases. The effect of uncertainty in $\gamma_F$ on the meson masses are examined. We also discuss a perspective on dynamical simulations.Comment: 19 pages, 15 eps figure

Numerical simulations of line-profile variation beyond a single-surface approximation for oscillations in roAp stars

Prior to the last decade, most observations of roAp stars have concerned the light variations. Recently some new, striking results of spectroscopic observations with high time resolution, high spectral dispersion, and a high signal-to-noise ratio became available. Since the oscillations found in roAp stars are high overtones, the vertical wavelengths of the oscillations are so short that the amplitude and phase of the variation of each spectroscopic line are highly dependent on the level of the line profile. Hence, analyses of the variation of the spectroscopic lines of roAp stars potentially provide us with new information about the vertical structure of the atmosphere of these stars. In order to extract such information, a numerical simulation of the line-profile variation beyond a single-surface approximation is necessary. We carried out a numerical simulation of line-profile variation by taking account of the finite thickness of the line forming layer. We demonstrated how effective this treatment is, by comparing the simulation with the observed line profiles.Comment: PASJ, 64, 9 (2012), in press. 18 pages, 16 figure

セルロース炭化の分子機構解明とその制御によるレボグルコサンの高効率生産

京都大学新制・課程博士博士(エネルギー科学)甲第23394号エネ博第421号新制||エネ||80(附属図書館)京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻(主査)教授 河本 晴雄, 教授 髙野 俊幸, 准教授 奥村 英之学位規則第4条第1項該当Doctor of Energy ScienceKyoto UniversityDFA

Re-thinking public library spaces with diversity and essential roles

Abstract. After the Internet was developed, public libraries started providing opportunities for many kinds of activities in addition to their traditional services, such as console games, making something in maker space, free Internet connection, and so on. Public library spaces have become more diverse to facilitate this change, and people can use them as free spaces. While this is an excellent way to increase the number of patrons, it seems that the share of people reading books is decreasing among the visitors. As libraries become more convenient and many people use them as free spaces, user interest in library materials is fading away, and thousands of materials have become just decoration. My diploma thesis aims to reorganize public library spaces to promote the essential roles of a library along with the embraced diverse new functions of the public library. Today, when the public library becomes freely used for a broader array of uses than simply reading and borrowing books, we need to rethink the spaces connecting patrons and literature because just placing books on rows of shelves in the library is no longer enough to make anyone read them. In the first part, I refer to current public library designs, concepts, and trends after the Internet has been commonized. I also discuss the future prospection of public libraries through a literature review to consider new public library designs. Secondly, I provide a brief review of design methodology, which approaches the interior and urban aspects to consider the optimal balance between diverse functions and essential roles. In the end, I show the new public library design in Fukushima City as an example of applying the methodology of my design approach. Through this diploma thesis, I suggest a design approach from both interior and urban perspectives as one of the ways to rethink the library space and attempt to see how it creates architecture in the actual site