148,955 research outputs found
A note on connected formula for form factors
In this note we study the connected prescription, originally derived from
Witten's twistor string theory, for tree-level form factors in
super-Yang-Mills theory. The construction is based on the recently proposed
four-dimensional scattering equations with massless on-shell states and one
off-shell state, which we expect to work for form factors of general operators.
To illustrate the universality of the prescription, we propose compact formulas
for super form factors with chiral stress-tensor multiplet operator, and
bosonic ones with scalar operators for arbitrary .Comment: 13 page
On the Precise Laplace Approximation for Large Deviations of Markov Chain The Nondegenerate Case
Abstract. Let Ln be the empirical measure of a uniformly er-godic nonreversible Markov chain on a compact metric space and Ī¦ be a smooth functional. This paper gives a precise asymptotic evalua-tion of the form E(exp(nĪ¦(Ln))) up to order 1 + o(1), in the case the Hessian of J āĪ¦ is nondegenerate, where J is the rate function of the large deviations of empirical measure
Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology
INE/AUTC 10.0
Globular Clusters in the Outer Halo of M31
In this paper, we present photometry of 53 globular clusters (GCs) in the M31
outer halo, including the {\sl GALEX} FUV and NUV, SDSS , 15
intermediate-band filters of BATC, and 2MASS bands. By comparing
the multicolour photometry with stellar population synthesis models, we
determine the metallicities, ages, and masses for these GCs, aiming to probe
the merging/accretion history of M31. We find no clear trend of metallicity and
mass with the de-projected radius. The halo GCs with age younger than
8 Gyr are mostly located at the de-projected radii around 100 kpc, but this may
be due to a selection effect. We also find that the halo GCs have consistent
metallicities with their spatially-associated substructures, which provides
further evidence of the physical association between them. Both the disk and
halo GCs in M31 show a bimodal luminosity distribution. However, we should
emphasize that there are more faint halo GCs which are not being seen in the
disk. The bimodal luminosity function of the halo GCs may reflect different
origin or evolution environment in their original hosts. The M31 halo GCs
includes one intermediate metallicity group ( [Fe/H] ) and one
metal-poor group ([Fe/H] ), while the disk GCs have one metal-rich group
more. There are considerable differences between the halo GCs in M31 and the
Milky Way (MW). The total number of M31 GCs is approximately three times more
numerous than that of the MW, however, M31 has about six times the number of
halo GCs in the MW. Compared to M31 halo GCs, the Galactic halo ones are mostly
metal-poor. Both the numerous halo GCs and the higher-metallicity component are
suggestive of an active merger history of M31.Comment: 14 pages, 16 figures, 6 tables. Accepted for publication in A&
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