1,636 research outputs found
M5-branes and Wilson Surfaces
We investigate the M5-brane description of the Wilson surface operators in
six-dimensional (2,0) superconformal field theory from AdS/CFT correspondence.
We consider the Wilson surface operators in high-dimensional representation,
whose description could be M5-brane string soliton solutions in background. We construct such string soliton solutions from the covariant
M5-brane equations of motion and discuss their properties. The supersymmetry
analysis shows that these solutions are half-BPS. We also discuss the subtle
issue on the boundary terms.Comment: 30 pages, Latex; little revision;Typos corrected, references added,
JHEP published versio
Hausdorff dimension of certain sets arising in continued fraction expansions
AbstractThis paper is concerned with the fractional dimensions of some sets of points with their partial quotients obeying some restrictions in their continued fraction expansions. The Hausdorff dimension of the following set, which shares a dichotomy law according to Borel–Bernstein's theorem, is completely determinedE(ϕ)={x∈[0,1):an(x)⩾ϕ(n), i.o. n}. Our result significantly strengthens the results of Good and Lúczak
A 7.0\% Determination of the Baryon Fraction in the Intergalactic Medium from Localized Fast Radio Bursts
The dispersion measure (DM)--redshift relation of fast radio bursts (FRBs)
has been proposed as a potential new tool for probing intergalactic medium
(IGM) and for studying cosmology. However, the poor knowledge of the baryon
fraction in the IGM () and its degeneracy with cosmological
parameters impose restrictions on the cosmological applications of FRBs.
Furthermore, DMs contributed by the IGM () and host galaxy
(), the important cosmological quantities, cannot be
exactly extracted from observations, which would bring uncontrolled systematic
uncertainties in FRB cosmology. In this work, we use seventeen localized FRBs
to constrain and possibly its redshift evolution. Other
cosmological probes such as Type Ia supernovae, baryon acoustic oscillations,
and cosmic microwave background radiation are combined to break parameter
degeneracy. Taking into account the probability distributions of
and derived from the the IllustrisTNG
simulation, we obtain a robust measurement of ,
representing a precision of 7.0\%. We find that there is no strong evidence for
the redshift dependence of at the current observational data
level. The rapid progress in localizing FRBs will significantly improve the
constraints on .Comment: 9 pages, 3 figures, 2 table
On the fast Khintchine spectrum in continued fractions
For , let be its continued fraction
expansion with partial quotients . Let be a function with as . In this note, the fast Khintchine spectrum, i.e., the Hausdorff
dimension of the set E(\psi):=\Big{x\in [0,1):
\lim_{n\to\infty}\frac{1}{\psi(n)}\sum_{j=1}^n\log a_j(x)=1\Big} is
completely determined without any extra condition on .Comment: 10 page
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