23,174 research outputs found
Critical exponents in quantum Einstein gravity
The quantum Einstein gravity is treated by the functional renormalization
group method using the Einstein-Hilbert action. The ultraviolet non-Gaussian
fixed point is determined and its corresponding exponent of the correlation
length is calculated for a wide range of regulators. It is shown that the
exponent provides a minimal sensitivity to the parameters of the regulator
which correspond to the Litim's regulator.Comment: 6 pages, 5 figure
Scalar Mesons and Glueballs in a Chiral U(3)xU(3) Quark Model with 't Hooft Interaction
In a U(3)x U(3) quark chiral model of the Nambu-Jona-Lasinio type with the 't
Hooft interaction, the ground scalar isoscalar mesons and a scalar glueball are
described. The glueball (dilaton) is introduced into the effective meson
Lagrangian written in a chirally symmetric form on the base of scale
invariance. The singlet-octet mixing of scalar isoscalar mesons and their
mixing with the glueball are taken into account. Mass spectra of the scalar
mesons and glueball and their strong decays are described.Comment: LaTeX2e, 13 pages, no figures, the equation for the divergence of
dilaton current is revised, the results are correcte
Ionization of atoms by few-cycle EUV laser pulses: carrier-envelope phase dependence of the intra-pulse interference effects
We have investigated the ionization of the H atom by intense few-cycle laser
pulses, in particular the intra-pulse interference effects, and their
dependence on the carrier-envelope phase (CEP) of the laser pulse. In the final
momentum distribution of the continuum electrons the imprint of two types of
intra-pulse interference effects can be observed, namely the temporal and
spatial interference. During the spatial interference electronic wave packets
emitted at the same time, but following different paths interfere leading to an
interference pattern measurable in the electron spectra. This can be also
interpreted as the interference between a direct and a scattered wave, and the
spatial interference pattern as the holographic mapping (HM) of the target.
This HM pattern is strongly influenced by the carrier-envelope phase through
the shape of the laser pulse. Here, we have studied how the shape of the HM
pattern is modified by the CEP, and we have found an optimal CEP for the
observation of HM
An octonionic formulation of the M-theory algebra
We give an octonionic formulation of the N = 1 supersymmetry algebra in D =
11, including all brane charges. We write this in terms of a novel outer
product, which takes a pair of elements of the division algebra A and returns a
real linear operator on A. More generally, with this product comes the power to
rewrite any linear operation on R^n (n = 1,2,4,8) in terms of multiplication in
the n-dimensional division algebra A. Finally, we consider the reinterpretation
of the D = 11 supersymmetry algebra as an octonionic algebra in D = 4 and the
truncation to division subalgebras
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