Thermal leptogenesis in a supersymmetric neutrinophilic Higgs model

We investigate thermal leptogenesis in a supersymmetric neutrinophilic Higgs model by taking phenomenological constraints into account, where, in addition to the minimal supersymmetric standard model, we introduce an extra Higgs field with a tiny vacuum expectation value (VEV) which generates neutrino masses. Thanks to this tiny VEV of the neutrinophilic Higgs, our model allows to reduce the mass of the lightest right-handed (s)neutrino to be ${\cal O}(10^5)$ GeV as keeping sufficiently large CP asymmetry in its decay. Therefore, the reheating temperature after inflation is not necessarily high, hence this scenario is free from gravitino problem.Comment: 5 pages, 1 figur

Unbinding Transition Induced by Osmotic Pressure in Relation to Unilamellar Vesicle Formation

Small-angle X-ray scattering and phase-contrast microscopy experiments were performed to investigate the effect of the osmotic pressure on vesicle formation in a dioleoylphosphatidylcholine (DOPC)/water/NaI system. Multi-lamellar vesicles were formed when a pure lipid film was hydrated with an aqueous solution of NaI. On the other hand, uni-lamellar vesicles (ULVs) were formed when a lipid film mixed with an enough amount of NaI was hydrated. To confirm the effect of the osmotic pressure due to NaI, a free-energy calculation was performed. This result showed that the osmotic pressure induced an unbinding transition on the hydration process, which resulted in ULV formation

Gravitational Wave Background from Neutrino-Driven Gamma-Ray Bursts

We discuss the gravitational wave background (GWB) from a cosmological population of gamma-ray bursts (GRBs). Among various emission mechanisms for the gravitational waves (GWs), we pay a particular attention to the vast anisotropic neutrino emissions from the accretion disk around the black hole formed after the so-called failed supernova explosions. The produced GWs by such mechanism are known as burst with memory, which could dominate over the low-frequency regime below \sim 10Hz. To estimate their amplitudes, we derive general analytic formulae for gravitational waveform from the axisymmetric jets. Based on the formulae, we first quantify the spectrum of GWs from a single GRB. Then, summing up its cosmological population, we find that the resultant value of the density parameter becomes roughly \Omega_{GW} \approx 10^{-20} over the wide-band of the low-frequency region, f\sim 10^{-4}-10^1Hz. The amplitude of GWB is sufficiently smaller than the primordial GWBs originated from an inflationary epoch and far below the detection limit.Comment: 6 pages, 4 figures, accepted for publication in MNRA

Gravitational Wave Astrometry for Rapidly Rotating Neutron Stars and Estimation of Their Distances

We discuss an astrometric timing effect on data analysis of continuous gravitational waves from rapidly rotating isolated neutron stars. Special attention is directed to the possibility of determining their distances by measuring the curvature of the wave fronts. We predict that if continuous gravitational waves from an unknown neutron star with a stable rotation are detected around 1kHz within 1/3yr by initial LIGO detectors and the ellipticity parameter epsilon is smaller than 10^{-6}, the distance r to the source can be estimated with relative error \Delta r/r of \sim 10% by using the broad band configuration of advanced LIGO detectors over 3 years. By combining the observed amplitude of the waves with the estimated distance, information on the parameter $\epsilon$ can be obtained purely through gravitational wave measurements.Comment: 6 pages, 1 figure, to appear in PR

Crystallization kinetics of binary colloidal monolayers

Experiments and simulations are used to study the kinetics of crystal growth in a mixture of magnetic and nonmagnetic particles suspended in ferrofluid. The growth process is quantified using both a bond order parameter and a mean domain size parameter. The largest single crystals obtained in experiments consist of approximately 1000 particles and form if the area fraction is held between 65-70% and the field strength is kept in the range of 8.5-10.5 Oe. Simulations indicate that much larger single crystals containing as many as 5000 particles can be obtained in impurity-free conditions within a few hours. If our simulations are modified to include impurity concentrations as small as 1-2%, then the results agree quantitatively with the experiments. These findings provide an important step toward developing strategies for growing single crystals that are large enough to enable follow-on investigations across many subdisciplines in condensed matter physics.Comment: 10 pages, 11 figure

Thermal leptogenesis in brane world cosmology

The thermal leptogenesis in brane world cosmology is studied. In brane world cosmology, the expansion law is modified from the four-dimensional standard cosmological one at high temperature regime in the early universe. As a result, the well-known upper bound on the lightest light neutrino mass induced by the condition for the out-of-equilibrium decay of the lightest heavy neutrino, $\tilde{m}_1 \lesssim 10^{-3}$ eV, can be moderated to be $\tilde{m}_1 \lesssim 10^{-3} {eV} \times (M_1/T_t)^2$ in the case of $T_t \leq M_1$ with the lightest heavy neutrino mass ($M_1$) and the ``transition temperature'' ($T_t$), at which the modified expansion law in brane world cosmology is smoothly connecting with the standard one. This implies that the degenerate mass spectrum of the light neutrinos can be consistent with the thermal leptogenesis scenario. Furthermore, as recently pointed out, the gravitino problem in supersymmetric case can be solved if the transition temperature is low enough $T_t \lesssim 10^{6-7}$ GeV. Therefore, even in the supersymmetric case, thermal leptogenesis scenario can be successfully realized in brane world cosmology.Comment: 9 pages, final versio

Optical Identification of Close White Dwarf Binaries in the LISA Era

The Laser Interferometer Space Antenna (LISA) is expected to detect close white dwarf binaries (CWDBs) through their gravitational radiation. Around 3000 binaries will be spectrally resolved at frequencies > 3 mHz, and their positions on the sky will be determined to an accuracy ranging from a few tens of arcminutes to a degree or more. Due to the small binary separation, the optical light curves of >~ 30% of these CWDBs are expected to show eclipses, giving a unique signature for identification in follow-up studies of the LISA error boxes. While the precise optical location improves binary parameter determination with LISA data, the optical light curve captures additional physics of the binary, including the individual sizes of the stars in terms of the orbital separation. To optically identify a substantial fraction of CWDBs and thus localize them very accurately, a rapid monitoring campaign is required, capable of imaging a square degree or more in a reasonable time, at intervals of 10--100 seconds, to magnitudes between 20 and 25. While the detectable fraction can be up to many tens of percent of the total resolved LISA CWDBs, the exact fraction is uncertain due to unknowns related to the white dwarf spatial distribution, and potentially interesting physics, such as induced tidal heating of the WDs due to their small orbital separation.Comment: 4 pages, 2 figure

Dynamical solutions of warped six dimensional supergravity

We derive a new class of exact time dependent solutions in a warped six dimensional supergravity model. Under the assumptions we make for the form of the underlying moduli fields, we show that the only consistent time dependent solutions lead to all six dimensions evolving in time, implying the eventual decompactification or collapse of the extra dimensions. We also show how the dynamics affects the quantization of the deficit angle.Comment: 18 pages, no figure, typos corrected, references added, the final versio

Pengenalan Pahlawan Indonesia Berbasis Augmented Reality dengan Marker Uang Indonesia

Perjuangan para Pahlawan Indonesia atau bisa disebut dengan Pahlawan Nasional sangatlah luar biasa, mulai dari melawan penjajah sampai memajukan Bangsa Indonesia. Berkat perjuangan yang sangat heroik, Pahlawan Nasional diabadikan gambarnya di dalam uang kertas Indonesia. Namun banyak masyarakat yang tidak mengetahui sejarah dari para Pahlawan Nasional yang terdapat pada uang kertas Indonesia terbaru tahun 2014. Berdasarkan hal tersebut penulis berusaha menyajikan suatu alternatif aplikasi dalam menampilkan 3D dan sejarah dari masing-masing Pahlawan Nasional yang terdapat pada uang kertas Indonesia dalam bentuk Augmented Reality dengan memanfaatkan smartphone android sebagai media penunjang dan uang kertas Indonesia sebagai marker. Dalam pembangunan aplikasi ini, metode yang digunakan adalah metode prototype. Prototype merupakan metodologi pengembangan software yang menitik beratkan pada pendekatan aspek desain, fungsi dan user-interface. Sistem prototyping dapat melakukan analisis, desain, dan tahapan pelaksanaan secara bersamaan agar cepat mengembangkan versi sederhana dari sistem yang diusulkan oleh user dan memberikannya kepada user untuk evaluasi dan pembenahan. Hasil analisis dan perancangan aplikasi ini memberikan kemudahan, meningkatkan efektivitas dan efisiensi bagi pengguna. Karena hanya bermodalkan smartphone android dan marker uang kertas Indonesia, pengguna hanya menjalankan aplikasi dan menyorotkan kamera smartphone ke uang kertas yang dimiliki kemuadian akan muncul 3D Pahlawan Indonesia yang terdapat pada uang yang disorotkan tersebut beserta indormasi atau sejarah dari Pahlawan tersebut