7,584 research outputs found
BRST invariant Lagrangian of spontaneously broken gauge theories in noncommutative geometry
The quantization of spontaneously broken gauge theories in noncommutative
geometry(NCG) has been sought for some time, because quantization is crucial
for making the NCG approach a reliable and physically acceptable theory. Lee,
Hwang and Ne'eman recently succeeded in realizing the BRST quantization of
gauge theories in NCG in the matrix derivative approach proposed by Coquereaux
et al. The present author has proposed a characteristic formulation to
reconstruct a gauge theory in NCG on the discrete space .
Since this formulation is a generalization of the differential geometry on the
ordinary manifold to that on the discrete manifold, it is more familiar than
other approaches. In this paper, we show that within our formulation we can
obtain the BRST invariant Lagrangian in the same way as Lee, Hwang and Ne'eman
and apply it to the SU(2)U(1) gauge theory.Comment: RevTeX, page
Dense and Warm Molecular Gas between Double Nuclei of the Luminous Infrared Galaxy NGC 6240
High spatial resolution observations of the 12CO(1-0), HCN(1-0), HCO+(1-0),
and 13CO(1-0) molecular lines toward the luminous infrared merger NGC 6240 have
been performed using the Nobeyama Millimeter Array and the RAINBOW
Interferometer. All of the observed molecular emission lines are concentrated
in the region between the double nuclei of the galaxy. However, the
distributions of both HCN and HCO+ emissions are more compact compared with
that of 12CO, and they are not coincident with the star-forming regions. The
HCN/12CO line intensity ratio is 0.25; this suggests that most of the molecular
gas between the double nuclei is dense. A comparison of the observed high
HCN/13CO intensity ratio, 5.9, with large velocity gradient calculations
suggests that the molecular gas is dense [n(H_2)=10^{4-6} cm^-3] and warm
(T_kin>50 K). The observed structure in NGC 6240 may be explained by time
evolution of the molecular gas and star formation, which was induced by an
almost head-on collision or very close encounter of the two galactic nuclei
accompanied with the dense gas and star-forming regions.Comment: 25 pages, 8 figures, To be appeared in PASJ 57, No.4 (August 25,
2005) issu
Arc-like distribution of high CO(J=3-2)/CO(J=1-0) ratio gas surrounding the central star cluster of the supergiant HII region NGC 604
We report the discovery of a high CO(J=3-2)/CO(J=1-0) ratio gas with an
arc-like distribution (``high-ratio gas arc'') surrounding the central star
cluster of the supergiant HII region NGC 604 in the nearby spiral galaxy M 33,
based on multi-J CO observations of a 5' 5' region of NGC 604
conducted using the ASTE 10-m and NRO 45-m telescopes. The discovered
``high-ratio gas arc'' extends to the south-east to north-west direction with a
size of 200 pc. The western part of the high-ratio gas arc closely
coincides well with the shells of the HII regions traced by H and radio
continuum peaks. The CO(J=3-2)/CO(J=1-0) ratio, R_{3-2/1-0}, ranges between 0.3
and 1.2 in the observed region, and the R_{3-2/1-0} values of the high-ratio
gas arc are around or higher than unity, indicating very warm (T_kin > 60 K)
and dense (n(H_2) > 10^{3-4} cm^{-3}) conditions of the high-ratio gas arc. We
suggest that the dense gas formation and second-generation star formation occur
in the surrounding gas compressed by the stellar wind and/or supernova of the
first-generation stars of NGC 604, i.e., the central star cluster of NGC 604.Comment: 4 pages, 4 figures. The Astrophysical Journal Letters, in pres
Experimental Line Parameters of the b^(1)ÎŁ^(+)_g â X^(3)ÎŁ^(-)_g Band of Oxygen Isotopologues at 760 nm Using Frequency-Stabilized Cavity Ring-Down Spectroscopy
Positions, intensities, self-broadened widths, and collisional narrowing coefficients of the oxygen isotopologues ^(16)O^(18)O, ^(16)O^(17)O, ^(17)O^(18)O, and ^(18)O^(18)O have been measured for the b^(1)ÎŁg + â X^(3)ÎŁg â (0,0) band using frequency-stabilized cavity ring-down spectroscopy. Line positions of 156 P-branch transitions were referenced against the hyperfine components of the ^(39)K D_1 (4s ^(2)S_(1/2) â 4p ^(2)P_(1/2)) and D_2 (4s ^(2)S_(1/2) â 4p ^(2)P_(3/2)) transitions, yielding precisions of ~0.00005 cm^(â1) and absolute accuracies of 0.00030 cm^(â1) or better. New excited b^(1)ÎŁg + state molecular constants are reported for all four isotopologues. The measured line intensities of the ^(16)O^(18)O isotopologue are within 2% of the values currently assumed in molecular databases. However, the line intensities of the ^(16)O^(17)O isotopologue show a systematic, J-dependent offset between our results and the databases. Self-broadening half-widths for the various isotopologues are internally consistent to within 2%. This is the first comprehensive study of the line intensities and shapes for the ^(17)O^(18)O or ^(18)O_2 isotopologues of the b^(1)ÎŁg + â X^(3)ÎŁg â (0,0) band of O_2. The ^(16)O_2, ^(16)O^(18)O, and ^(16)O^(17)O line parameters for the oxygen A-band have been extensively revised in the HITRAN 2008 database using results from the present study
Line voltage detector for SMES system designed to protect from momentary voltage drop
For the precision industrial plants, a stable electrical power source is the one of the key components as known as well. Usually, a battery type UPS is used to protect computers from the power failure, but it cannot protect the whole plant because its capacity is too small to supply for all facilities. A short time SMES system is suitable to cover this problem. It will supply the enough power to the plant while the line voltage is momentary dropped. The target plant may be sensitive for the line voltage drop, a high-speed detection of voltage drop is required and a detector that uses two detect method in parallel, was developed. This paper introduces the voltage detector developed for the SMES system
Millimeter- and Submillimeter-Wave Observations of the OMC-2/3 Region. II. Observational Evidence for Outflow-Triggered Star Formation in the OMC-2 FIR 3/4 Region
We have carried out the observations of the OMC-2 FIR 3/4 region with the NMA
and ASTE in the HCO (1--0), CO (3--2, 1--0), SiO (=0,
=2--1), CS (2--1), and CHOH (=7--6) lines and in the 3.3 mm
continuum emission. Our NMA observations in the HCO emission have
revealed 0.07 pc-scale dense gas associated with FIR 4. The CO
(3--2,1--0) emission shows high-velocity blue and red shifted components at the
both north-east and south-west of FIR 3, suggesting a molecular outflow nearly
along the plane of the sky driven by FIR 3. The SiO and the CHOH emission
are detected around the interface between the outflow and the dense gas.
Furthermore, the CO (1--0) emission shows an L-shaped structure in the
P-V diagram. These results imply presence of the shock due to the interaction
between the molecular outflow driven by FIR 3 and the dense gas associated with
FIR 4. Moreover, our high angular-resolution observations of FIR 4 in the 3.3
mm continuum emission have first found that FIR 4 consists of eleven dusty
cores. The separation among these cores is on the same order of the Jeans
length, suggesting that the fragmentation into these cores has been caused by
the gravitational instability. The time scale of the fragmentation is similar
to the time scale of the interaction between the molecular outflow and the
dense gas. We suggest that the interaction between the molecular outflow from
FIR 3 and the dense gas associated with FIR 4 triggered the fragmentation into
these dusty cores, and hence the next generation the cluster formation.Comment: 13 pages, 9 figures. Accepted by Ap
Kinetics of n-Butoxy and 2-Pentoxy Isomerization and Detection of Primary Products by Infrared Cavity Ringdown Spectroscopy
The primary products of n-butoxy and 2-pentoxy isomerization in the presence and absence of O_2 have been detected using pulsed laser photolysis-cavity ringdown spectroscopy (PLP-CRDS). Alkoxy radicals n-butoxy and 2-pentoxy were generated by photolysis of alkyl nitrite precursors (n-butyl nitrite or 2-pentyl nitrite, respectively), and the isomerization products with and without O_2 were detected by infrared cavity ringdown spectroscopy 20 Îźs after the photolysis. We report the mid-IR OH stretch (ν_1) absorption spectra for δ-HO-1-C_4H_8â˘, δ-HO-1-C_4H_8OOâ˘, δ-HO-1-C_5H_(10)â˘, and δ-HO-1-C_5H_(10)OOâ˘. The observed ν_1 bands are similar in position and shape to the related alcohols (n-butanol and 2-pentanol), although the HOROO⢠absorption is slightly stronger than the HOR⢠absorption. We determined the rate of isomerization relative to reaction with O_2 for the n-butoxy and 2-pentoxy radicals by measuring the relative ν_1 absorbance of HOROO⢠as a function of [O_2]. At 295 K and 670 Torr of N_2 or N_2/O_2, we found rate constant ratios of k_(isom)/k_(O2) = 1.7 (Âą0.1) Ă 10^(19) cm^(â3) for n-butoxy and k_(isom)/k_(O2) = 3.4(Âą0.4) Ă 10^(19) cm^(â3) for 2-pentoxy (2Ď uncertainty). Using currently known rate constants k_(O2), we estimate isomerization rates of k_(isom) = 2.4 (Âą1.2) Ă 10^5 s^(â1) and k_(isom) â 3 Ă 10^5 s^(â1) for n-butoxy and 2-pentoxy radicals, respectively, where the uncertainties are primarily due to uncertainties in k_(O2). Because isomerization is predicted to be in the high pressure limit at 670 Torr, these relative rates are expected to be the same at atmospheric pressure. Our results include corrections for prompt isomerization of hot nascent alkoxy radicals as well as reaction with background NO and unimolecular alkoxy decomposition. We estimate prompt isomerization yields under our conditions of 4 Âą 2% and 5 Âą 2% for n-butoxy and 2-pentoxy formed from photolysis of the alkyl nitrites at 351 nm. Our measured relative rate values are in good agreement with and more precise than previous end-product analysis studies conducted on the n-butoxy and 2-pentoxy systems. We show that reactions typically neglected in the analysis of alkoxy relative kinetics (decomposition, recombination with NO, and prompt isomerization) may need to be included to obtain accurate values of k_(isom)/k_(O2)
Effects of sacubitril/valsartan in the PARADIGM-HF Trial (Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) according to background therapy
BackgroundâIn the PARADIGM-HF trial (Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure), the angiotensin receptor neprilysin inhibitor sacubitril/valsartan was more effective than the angiotensin-converting enzyme inhibitor enalapril in patients with heart failure and reduced ejection fraction. We examined whether this benefit was consistent irrespective of background therapy.
Methods and ResultsâWe examined the effect of study treatment in the following subgroups: diuretics (yes/no), digitalis glycoside (yes/no), mineralocorticoid receptor antagonist (yes/no), and defibrillating device (implanted defibrillating device, yes/no). We also examined the effect of study drug according to β-blocker dose (âĽ50% and <50% of target dose) and according to whether patients had undergone previous coronary revascularization. We analyzed the primary composite end point of cardiovascular death or heart failure hospitalization, as well as cardiovascular death. Most randomized patients (n=8399) were treated with a diuretic (80%) and β-blocker (93%); 47% of those taking a β-blocker were treated with âĽ50% of the recommended dose. In addition, 4671 (56%) were treated with a mineralocorticoid receptor antagonist, 2539 (30%) with digoxin, and 1243 (15%) had a defibrillating device; 2640 (31%) had undergone coronary revascularization. Overall, the sacubitril/valsartan versus enalapril hazard ratio for the primary composite end point was 0.80 (95% confidence interval, 0.73â0.87; P<0.001) and for cardiovascular death was 0.80 (0.71â0.89; P<0.001). The effect of sacubitril/valsartan was consistent across all subgroups examined. The hazard ratio for primary end point ranged from 0.74 to 0.85 and for cardiovascular death ranged from 0.75 to 0.89, with no treatment-by-subgroup interaction.
ConclusionsâThe benefit of sacubitril/valsartan, over an angiotensin-converting enzyme inhibitor, was consistent regardless of background therapy and irrespective of previous coronary revascularization or β-blocker dose
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