17,733 research outputs found
Scale dependence of cosmological backreaction
Due to the non-commutation of spatial averaging and temporal evolution,
inhomogeneities and anisotropies (cosmic structures) influence the evolution of
the averaged Universe via the cosmological backreaction mechanism. We study the
backreaction effect as a function of averaging scale in a perturbative approach
up to higher orders. We calculate the hierarchy of the critical scales, at
which 10% effects show up from averaging at different orders. The dominant
contribution comes from the averaged spatial curvature, observable up to scales
of 200 Mpc. The cosmic variance of the local Hubble rate is 10% (5%) for
spherical regions of radius 40 (60) Mpc. We compare our result to the one from
Newtonian cosmology and Hubble Space Telescope Key Project data.Comment: 6 pages, 2 figures; v3: substantial modifications, new figure
TINJAUAN HUKUM PENGATURAN HAK CIPTA SEBAGAI OBJEK JAMINAN FIDUSIA MENURUT UNDANG-UNDANG NOMOR 28 TAHUN 2014 TENTANG HAK CIPTA
Tujuan dilakukannya penelitian untuk mengetahui bagaimana pengaturan Hak Cipta yang dapat dijadikan sebagai obyek jaminan fidusia dan bagaimana sistem pendaftaran Hak Cipta menurut Undang-Undang Hak Cipta yang dengan metode penelitian hukum normatif disimpulkan: 1. Fungsi pendaftaran hak cipta adalah pertama hak atas ciptaan baru yang mempunyai kekuatan dan kedua pendaftaran itu bukanlah menerbitkan hak, melainkan hanya memberikan dugaan atau sangkaan saja bahwa orang yang hak ciptanya terdaftar itu adalah si berhak sebenarnya sebagai pencipta dari hak yang didaftarkannya. Jika didaftarkan secara konstitutif hak cipta itu diakui keberadaannya secara de jure dan defacto sedangkan secara deklaratif titik beratnya diletakkan pada anggapan sebagai pencipta terhadap hak yang didaftarkan sampai orang lain dapat membuktikan sebaliknya. Pendaftaran bukanlah syarat untuk sahnya suatu hak cipta, melainkan hanya untuk memudahkan suatu pembuktian bila terjadi sengketa. Pendaftaran dapat memberikan kepastian hukum serta lebih memudahkan dalam prosedur pengalihan hak. 2. Hak Cipta dapat dijadikan obyek jaminan fidusia diatur di dalam Pasal 16 ayat (4) dilaksanakan sesuai ketentuan perundang-undangan yang berlaku dalam hal ini adalah undang-undang jaminan fidusia dan undang-undang perbankan. Hak cipta merupakan benda bergerak tidak berwujud dapat dijadikan obyek jaminan fidusia (Pasal 16 ayat (1 dan 3), telah memenuhi persyaratan dalam undang-undang jaminan fidusia dimana dalam Pasal 1 ayat (2) yang menjadi obyek jaminan fidusia adalah jaminan atas benda bergerak baik yang berwujud maupun yang tidak berwujud. Dalam pelaksanaanya hak cipta yang dijadikan obyek jaminan fidusia berkaitan erat dengan perbankan sebagai kreditur yang memberikan kredit. Berdasarkan Undang-Undang Perbankan Nomor 10 Tahun 1998 tentang Perubahan atas UU Nomor 7 Tahun 1992 tentang Perbankan, fungsi utama bank sebagai penghimpun dana dan penyalur dana, dalam melakukan usahanya berasaskan demokrasi dengan menggunakan prinsip kehati-hatian. (Pasal 2 dan 3). Hak cipta sebagai obyek jamian fidusia merupakan hal yang baru sehingga pihak bank tidak serta merta dapat melaksanakannya karena perlu penjabaran yang lebih lanjut dalam peraturan seperti untuk menilai hak cipta yang dijadikan obyek jaminan apakah benar-benar memiliki nilai yang tinggi sehingga nantinya tidak akan merugikan pihak bank.Kata kunci: hak cipta; fidusia
Quantization and holomorphic anomaly
We study wave functions of B-model on a Calabi-Yau threefold in various
polarizations.Comment: 15 page
Evidence of sympathetic cooling of Na+ ions by a Na MOT in a hybrid trap
A hybrid ion-neutral trap provides an ideal system to study collisional
dynamics between ions and neutrals. This system provides a general cooling
method that can be applied to optically inaccessible species and can also
potentially cool internal degrees of freedom. The long range polarization
potentials () between ions and neutrals result in large
scattering cross sections at cold temperatures, making the hybrid trap a
favorable system for efficient sympathetic cooling of ions by collisions with
neutral atoms. We present experimental evidence of sympathetic cooling in a
hybrid trap of \ce{Na+} ions, which are closed shell and therefore do not have
a laser induced atomic transition, by equal mass cold Na atoms in a
magneto-optical trap (MOT).Comment: 7 figure
The spectroscopic evolution of the -ray emitting classical nova Nova Mon 2012. I. Implications for the ONe subclass of classical novae
Nova Mon 2012 was the first classical nova to be detected as a high energy
-ray transient, by Fermi-LAT, before its optical discovery. We study a
time sequence of high resolution optical echelle spectra (Nordic Optical
Telescope) and contemporaneous NOT, STIS UV, and CHIRON echelle spectra (Nov
20/21/22). We use [O III] and H line fluxs to constrain the properties
of the ejecta. We derive the structure from the optical and UV line profiles
and compare our measured line fluxes for with predictions using Cloudy with
abundances from other ONe novae. Mon 2012 is confirmed as an ONe nova. We find
E(B-V)=0.850.05 and hydrogen column density
cm. The corrected continuum luminosity is nearly the same in the entire
observed energy range as V1974 Cyg, V382 Mon, and Nova LMC 2000 at the same
epoch after outburst. The distance, about 3.6 kpc, is quite similar to V1974
Cyg. The line profiles can be modeled using an axisymmetric bipolar geometry
for the ejecta with various inclinations of the axis to the line of sight, 60
\le i \le 80 degrees, an opening angle of \approx\Delta
R/R(t)\approx 0.4f\approx 0.1-0.3\leq 6\times
10^{-5}_\odot\gamma$-ray emission may be a generic phenomenon, common to all ONe novae,
possibly to all classical novae, and connected with acceleration and emission
processes within the ejecta (abstract severely truncated).Comment: Submitted to A&A 9/1/2013; Accepted 27/2/2013 (in press
The spectroscopic evolution of the recurrent nova T Pyxidis during its 2011 outburst. II.The optically thin phase and the structure of the ejecta in recurrent novae
We continue our study of the physical properties of the recurrent nova T Pyx,
focussing on the structure of the ejecta in the nebular stage of expansion
during the 2011 outburst. The nova was observed contemporaneously with the
Nordic Optical Telescope (NOT), at high resolution spectroscopic resolution (R
~ 65000) on 2011 Oct. 11 and 2012 Apr. 8 (without absolute flux calibration),
and with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble
Space Telescope, at high resolution (R ~ 30000) on 2011 Oct. 10 and 2012 Mar.
28 (absolute fluxes). We use standard plasma diagnostics (e.g. [O III] and [N
II] line ratios and the H line fluxes) to constrain electron densities
and temperatures. Using Monte Carlo modeling of the ejecta, we derive the
structure and filling factor from comparisons to the optical and ultraviolet
line profiles. The ejecta can be modeled using an axisymmetric conical --
bipolar -- geometry with a low inclination of the axis to the line of sight,
i=15+/-5 degrees, compatible with published results from high angular
resolution optical spectro-interferometry. The structure is similar to that
observed in the other short orbital period recurrent novae during their nebular
stages. We show that the electron density scales as as expected from a
ballistically ejected constant mass shell; there is no need to invoke a
continuing mass outflow following the eruption. The derived mass for the ejecta
with filling factor f ~ 3%, M_ej ~ 2E-6$M_sun is similar to that obtained for
other recurrent nova ejecta but inconsistent with the previously reported
extended optically thick epoch of the explosion. We suggest that the system
underwent a common envelope phase following the explosion that produced the
recombination event. Implications for the dynamics of the recurrent novae are
discussed. (truncated)Comment: accepted for publication in A&A (10 Nov. 2012), 10 pgs, 16 fig
Ion-neutral sympathetic cooling in a hybrid linear rf Paul and magneto-optical trap
Long range polarization forces between ions and neutral atoms result in large
elastic scattering cross sections, e.g., 10^6 a.u. for Na+ on Na or Ca+ on Na
at cold and ultracold temperatures. This suggests that a hybrid ion-neutral
trap should offer a general means for significant sympathetic cooling of atomic
or molecular ions. We present SIMION 7.0 simulation results concerning the
advantages and limitations of sympathetic cooling within a hybrid trap
apparatus, consisting of a linear rf Paul trap concentric with a Na
magneto-optical trap (MOT). This paper explores the impact of various heating
mechanisms on the hybrid system and how parameters related to the MOT, Paul
trap, number of ions, and ion species affect the efficiency of the sympathetic
cooling
Comet Machholz (C/2004 Q2): morphological structures in the inner coma and rotation parameters
Extensive observations of comet C/2004 Q2 (Machholz) were carried out between
August 2004 and May 2005. The images obtained were used to investigate the
comet's inner coma features at resolutions between 350 and 1500 km/pixel. A
photometric analysis of the dust outflowing from the comet's nucleus and the
study of the motion of the morphological structures in the inner coma indicated
that the rotation period of the nucleus was most likely around 0.74 days. A
thorough investigation of the inner coma morphology allowed us to observe two
main active sources on the comet's nucleus, at a latitude of +85{\deg} \pm
5{\deg} and +45{\deg} \pm 5{\deg}, respectively. Further sources have been
observed, but their activity ran out quite rapidly over time; the most relevant
was at latcom. = 25{\deg} \pm 5{\deg}. Graphic simulations of the geometrical
conditions of observation of the inner coma were compared with the images and
used to determine a pole orientation at RA=95{\deg} \pm 5{\deg}, Dec=+35{\deg}
\pm 5{\deg}. The comet's spin axis was lying nearly on the plane of the sky
during the first decade of December 2004.Comment: 29 pages, 8 figures, 3 table
Tycho Brahe's supernova: light from centuries past
The light curve of SN 1572 is described in the terms used nowadays to
characterize SNeIa. By assembling the records of the observations done in
1572--74 and evaluating their uncertainties, it is possible to recover the
light curve and the color evolution of this supernova. It is found that, within
the SNe Ia family, the event should have been a SNIa with a normal rate of
decline, its stretch factor being {\it s} 0.9. Visual light curve near
maximum, late--time decline and the color evolution sustain this conclusion.
After correcting for extinction, the luminosity of this supernova is found to
be M --19.58 --5 log (D/3.5 kpc) 0.42.Comment: 28 pages, 3 figures, 3 tables. submitted to ApJ (Main Journal
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