12060817
MORE ON THE SIMILARITY BETWEEN D = 5 SIMPLE SUPERGRAVITY AND M THEORY
Abstract It has been known that D =5 simple supergravity resembles D =11 supergravity in many respects. We present their further resemblances in (1) the duality groups upon dimensional reduction, and (2) the worldsheet structure of the solitonic string of the D =5 supergravity. We show that the D =3, G 2(+2) / SO (4) (bosonic) nonlinear sigma model is obtained by using Freudenthal's construction in parallel to the derivation of the D =3, E 8(+8) / SO (16) sigma model from D =11 supergravity. The zero modes of the string solution with unbroken (4,0) supersymmetry consist of three (non-chiral) scalars, four Majorana-Weyl spinors of the same chirality and one chiral scalar, which suggests a duality to a certain six-dimensional chiral string theory. The worldsheet gravitational anomaly indicates a quantum correction to the Bianchi identity for the dualized two-form gauge field in the bulk just like the M5-brane case.
119274935
General Kaluza-Klein black holes with all six independent charges in five-dimensional minimal supergravity
Using the SL(2,R)-duality in a dimensionally reduced spacetime in (the bosonic sector of) five-dimensional minimal supergravity, we construct general Kaluza-Klein black hole solutions which carry six independent charges, its mass, angular momentum along four dimensions, electric and magnetic charges of the Maxwell fields in addition to Kaluza-Klein electric and magnetic monopole charges.
119918939
BRST Structure of the W3 Minimal Model
We construct explicitly the BRST structure of the W 3 extended minimal models. We also discuss several applications of our construction
118497701
Chiral generations on intersecting 5-branes in heterotic string theory
We show that there exist two 27 and one $$ \bold{\overline {27}} $$ of E6, net one D = 4, $$ \mathcal{N} $$ = 1 chiral matter supermultiplet as zero modes localized on the intersection of two 5-branes in the E8 × E8 heterotic string theory. The smeared intersecting 5-brane solution is used via the standard embedding to construct a heterotic background, which provides, after a compactification of some of the transverse dimensions, a five-dimensional Randall-Sundrum II like brane-world set-up in heterotic string theory. As a by-product, we present a new proof of anomaly cancellation between those from the chiral matter and the anomaly inflow onto the brane without small instanton.
118339648
Family unification via quasi-Nambu–Goldstone fermions in string theory
Some of the supersymmetric nonlinear sigma models on exceptional groups (E7 or E8) are known to yield almost minimal necessary content of matter fields for phenomenological model building, including three chiral families and a Higgs multiplet. We explore a possible realization of such a family unification in heterotic string theory, where the spontaneously broken symmetry that we focus on is the one associated with the change of global orientation of the spin bundle embedded in the gauge bundle, which cannot be ignored in the presence of a magnetic source of the B field. We show in a simple model that it indeed gives rise to chiral matter fields on the defect similarly to the domain-wall fermions, and compare the chiral zero mode spectrum with the sigma model. The setup is reduced to a system similar to that postulated in the orbifold GUT or the grand gauge-Higgs unification model, where the origin of Z2 identification is accounted for as arising from the bolt of the Atiyah-Hitchin manifold.
33408165
BPS saturation from null reduction
We show that any d-dimensional strictly stationary, asymptotically Minkowskian solution of a null reduction of (d + 1)-dimensional pure gravity must saturate the BPS bound if the spacetime admits another commuting Killing vector field so that the Kaluza-Klein vector field can be identified appropriately. We also argue that it is consistent with the field equations.
119301785
Five-year optical and near-infrared observations of the extremely slow nova V1280 Scorpii ,
We present optical (B, V, R c , I c and y) and near-infrared (J, H, and K s ) photometric and spectroscopic observations of a classical nova V 1280 Scorpii for five years from 2007 to 2011. Our photometric observations show a declining event in optical bands shortly after the maximum light, which took about 250 days to recover. This event was most probably caused by dust formation. The event was accompanied by a short (∼30 days) re-brightening episode (∼2.5 mag in V), which suggests that there had been some re-ignition of the surface nuclear burning. After 2008, the y band observations show a very long plateau at around y = 10.5 for more than 1000 days until April 2011 (∼1500 days after the maximum light). The nova had taken a very long time (∼50 months) to enter the nebular phase, according to a clear detection of both [O III] 4959 and 5007 and is still continuing to generate the wind caused by H-burning. This finding suggests that historically V1280 Sco is evolving at its slowest ever measured rate. The interval from the maximum light (2007 February 16) to the beginning of the nebular phase is longer than any previously known slow novae: V723 Cas (18 months), RR Pic (10 months), or HR Del (8 months). It suggests that the mass of a white dwarf in the V1280 Sco system might be 0.6 M ⊙ or lower. The distance, based on our measurements of the expansion velocity combined with the directly measured size of the dust shell, is estimated to be 1.1 ± 0.5 kpc.
119197153
Optical light curves of RS Oph (2006) and hydrogen burning turnoff
We report a coordinated multi-band photometry of the RS Oph 2006 outburst and highlight the emission line free y-band photometry that shows a mid-plateau phase at y ~ 10.2 mag from day 40 to day 75 after the discovery followed by a sharp drop of the final decline. Such mid-plateau phases are observed in other two recurrent novae, U Sco and CI Aql, and are interpreted as a bright disk irradiated by the white dwarf. We have calculated theoretical light curves based on the optically thick wind theory and have reproduced the early decline, mid-plateau phase, and final decline. The final decline is identified with the end of steady hydrogen shell-burning, which turned out at about day 80. This turnoff date is consistent with the end of a supersoft X-ray phase observed with Swift. Our model suggests a white dwarf mass of 1.35 \pm 0.01 M_\sun, which indicates that RS Oph is a progenitor of Type Ia supernovae. We strongly recommend the y-filter observation of novae to detect both the presence of a disk and the hydrogen burning turnoff. Observational data of y magnitudes are provided here together with other multi-wavelength light curve data.
118546306
Discovery of Multiple High-Velocity Narrow Circumstellar NaI D Lines in Nova V1280 Sco
We discovered multiple high-velocity (ranging from � 900 to � 650 km s � 1 ) and narrow (FWHM � 15 km s � 1 ) absorption components corresponding to both the D2 and the D1 lines of Na I on a high-dispersion spectrum of V1280 Sco, observed on 2009 May 9 (UT), 814 d after the V band maximum. Subsequent observations carried out on 2009 June and July confirmed at least 11 distinct absorption components in both systems. Some components had deepened during the two-month period while their HWHMs and wavelengths remained nearly constant. We suggest that these high-velocity components originated in cool clumpy gas clouds moving on the line-of-sight, produced during interactions between pre-existing cool circumstellar gas and high-velocity gas ejected in the nova explosion. The optical region spectrum of V1280 Sco in 2009 is dominated by the continuum radiation, and exhibits no forbidden line characterizing the nebular phase of typical novae. Permitted Fe II lines show doubly peaked emission profiles, and some strong Fe II lines are accompanied by a blue-shifted ( �� 255 km s � 1 ) absorption component. However, no high-velocity and narrow components corresponding to those of Na I could be detected in Fe II lines nor in the Balmer lines. The 255 km s � 1 low-velocity absorption component most probably originates in the wind from the nova.