Constraints on f(R) cosmologies from strong gravitational lensing systems

f(R) gravity is thought to be an alternative to dark energy which can explain the acceleration of the universe. It has been tested by different observations including type Ia supernovae (SNIa), the cosmic microwave background (CMB), the baryon acoustic oscillations (BAO) and so on. In this Letter, we use the Hubble constant independent ratio between two angular diameter distances $D=D_{ls}/D_s$ to constrain f(R) model in Palatini approach $f(R)=R-\alpha H^2_0(-\frac{R}{H^2_0})^\beta$. These data are from various large systematic lensing surveys and lensing by galaxy clusters combined with X-ray observations. We also combine the lensing data with CMB and BAO, which gives a stringent constraint. The best-fit results are $(\alpha,\beta)=(-1.50,0.696)$ or $(\Omega_m,\beta)=(0.0734,0.696)$ using lensing data only. When combined with CMB and BAO, the best-fit results are $(\alpha,\beta)=(-3.75,0.0651)$ or $(\Omega_m,\beta)=(0.286,0.0651)$. If we further fix $\beta=0$ (corresponding to $\Lambda$CDM), the best-fit value for $\alpha$ is $\alpha$=$-4.84_{-0.68}^{+0.91}(1\sigma)_{-0.98}^{+1.63}(2\sigma)$ for the lensing analysis and $\alpha$=$-4.35_{-0.16}^{+0.18}(1\sigma)_{-0.25}^{+0.3}(2\sigma)$ for the combined data, respectively. Our results show that $\Lambda$CDM model is within 1$\sigma$ range.Comment: 9 pages, 2 figures, 2 table

Perbedaan Sikap antara Li Ping dan Bao Xiruo

Skripsi ini menganalisi sebuah novel berjudul Pendekar Pemanah Rajawali karangan Jin Yong. Di dalam novel ini terdapat dua orang tokoh pembantu yang sangat mempengaruhi kedua tokoh utama dalam novel, yaitu Li Ping dan Bao Xiruo. Li Ping adalah ibu dari Guo Jing, sedangkan Bao Xiruo adalah ibu dari Yang Kang. Tujuan dari penulisan ini adalah untuk mengetahui perbedaan pengajaran antara Li Ping, ibu dari Guo Jing dan Bao Xiruo, ibu dari Yang Kang. Studi ini menggunakan teori penokohan yang diterapkan dalam tokoh Li Ping dan Bao Xiruo untuk mempelajari lebih lanjut sikap-sikap yang mereka miliki, teori konflik juga ditujukan dalam tokoh Li Ping dan Bao Xiruo untuk lebih memahami sikap yang mereka miliki

Standard rulers, candles, and clocks from the low-redshift Universe

We measure the length of the Baryon Acoustic Oscillation (BAO) feature, and the expansion rate of the recent Universe, from low-redshift data only, almost model-independently. We make only the following minimal assumptions: homogeneity and isotropy; a metric theory of gravity; a smooth expansion history, and the existence of standard candles (supernov\ae) and a standard BAO ruler. The rest is determined by the data, which are compilations of recent BAO and Type IA supernova results. Making only these assumptions, we find for the first time that the standard ruler has length $103.9 \pm 2.3\, h^{-1}$ Mpc. The value is a measurement, in contrast to the model-dependent theoretical prediction determined with model parameters set by Planck data ($99.3 \pm 2.1 \, h^{-1}$ Mpc). The latter assumes $\Lambda$CDM, and that the ruler is the sound horizon at radiation drag. Adding passive galaxies as standard clocks or a local Hubble constant measurement allows the absolute BAO scale to be determined ($142.8\pm 3.7$ Mpc), and in the former case the additional information makes the BAO length determination more precise ($101.9\pm 1.9 \, h^{-1}\,$Mpc). The inverse curvature radius of the Universe is weakly constrained and consistent with zero, independently of the gravity model, provided it is metric. We find the effective number of relativistic species to be $N_{\rm eff} = 3.53\pm 0.32$, independent of late-time dark energy or gravity physics.Comment: Accepted for publication in PRL. 5 pages, 4 figure

Amy D. Dooling and Kristina M. Torgeson, eds. Writing women in modern China : an anthology of women\u27s literature from the early twentieth century

This article reviews the book Writing Women in Modern China: An Anthology of Women\u27s Literature from the Early Twentieth Century edited by Amy D. Dooling and Kristina M. Torgeson

Public Administration Reform in a Transitional Economy: Case of Vietnam

This paper examines Vietnam’s institutional debates and reforms during 1987-1997. It maintains that the country has started “renovation process” due to the collapse of the Soviet bloc in the late 1980s and early 1990s. Identification and analysis of the problems and challenges show that the prescription for economic reforms cannot be effectively carried out without an efficient administrative capacity to manage the change.governance

Effect of Ph on the Magnetic and Microstructure Properties of the Barium Hexaferrite

BaO.6Fe2O3 magnet materials have been successfully synthesized by co-precipitation method from the precursor solution with pH = 9 and pH = 12. The characterization was done by means of X-Ray Diffractometer (XRD), Vibrating Sample Magnetometer (VSM), Differential Thermal Analyses (DTA)/Thermal GravimetricAnalysis (TGA), Scanning ElectronMicroscope (SEM) and Transmission Electron Microscope (TEM). The results ofmagnetic properties measurement using VSM showed that sintered BaO.6Fe2O3 at 800 oC from precursor with pH = 12 has highest magnetic coercivity Hci = 5.6 kOe. High magnetic coercivity is likely due to the very fine crystallites size approach single-domain. This is supported by SEM and TEM observations show that the length of the BaO.6Fe2O3 particle size is about 50-150 nm after sintering process at 800 oC. Thus BaO.6Fe2O3 materials obtained from this activity can be classified as the high-energy magnet hexaferrite which has a great potential to be used as a component of energy generation

Public Administration Reform in a Transitional Economy: Case of Vietnam

This paper examines Vietnam’s institutional debates and reforms during 1987-1997. It maintains that the country has started “renovation process” due to the collapse of the Soviet bloc in the late 1980s and early 1990s. Identification and analysis of the problems and challenges show that the prescription for economic reforms cannot be effectively carried out without an efficient administrative capacity to manage the change.governance