5,777 research outputs found
Understanding the Heterogeneity of Contributors in Bug Bounty Programs
Background: While bug bounty programs are not new in software development, an
increasing number of companies, as well as open source projects, rely on
external parties to perform the security assessment of their software for
reward. However, there is relatively little empirical knowledge about the
characteristics of bug bounty program contributors. Aim: This paper aims to
understand those contributors by highlighting the heterogeneity among them.
Method: We analyzed the histories of 82 bug bounty programs and 2,504 distinct
bug bounty contributors, and conducted a quantitative and qualitative survey.
Results: We found that there are project-specific and non-specific contributors
who have different motivations for contributing to the products and
organizations. Conclusions: Our findings provide insights to make bug bounty
programs better and for further studies of new software development roles.Comment: 6 pages, ESEM 201
Boron abundance and solar neutrino spectrum distortion
The presence of neutrinos from Boron decay in the flux observed on Earth is
attested by the observation of their energy spectrum. Possible distortions of
the spectrum investigated in current detectors are often interpreted in terms
of evidence in favour or against various schemes of neutrino oscillations. We
stress here that a distortion of the spectrum at high energies could also
result from an increase in the ratio of neutrinos originating from (He+p)
and B reactions. While a B neutrino depletion would contribute to this
effect, an increase in the Hep contribution seems also needed to reproduce the
preliminary data.Comment: 8 pages, 2 figures; abstract and introduction rewritten to match the
conclusions bette
The Perturbative Spectrum of the Dressed Sliver
We analyze the fluctuations of the dressed sliver solution found in a
previous paper, hep-th/0311198, in the operator formulation of Vacuum String
Field Theory. We derive the tachyon wave function and then analyze the higher
level fluctuations. We show that the dressing is responsible for implementing
the transversality condition on the massless vector. In order to consistently
deal with the singular mode we introduce a string midpoint regulator and
we show that it is possible to accommodate all the open string states among the
solutions to the linearized equations of motion. We finally show how the
dressing can give rise to the correct ratio between the energy density of the
dressed sliver and the brane tension computed via the three-tachyons-coupling.Comment: 52 pages, v2: comment added in sec. 5, v3: one appendix added,
comments added in introduction and conclusion, to appear on PR
Boundary states as exact solutions of (vacuum) closed string field theory
We show that the boundary states are idempotent B*B=B with respect to the
star product of HIKKO type closed string field theory. Variations around the
boundary state correctly reproduce the open string spectrum with the gauge
symmetry. We explicitly demonstrate it for the tachyonic and massless vector
modes. The idempotency relation may be regarded as the equation of motion of
closed string field theory at a possible vacuum.Comment: 30 pages, 2 figures, v3:regularization improve
Comments on Supersymmetry Algebra and Contact Term in Matrix String Theory
Following hep-th/0309238 relating the matrix string theory to the light-cone
superstring field theory, we write down two supercharges in the matrix string
theory explicitly. After checking the supersymmetry algebra at the leading
order, we proceed to discuss higher-order contact terms.Comment: 17 pages, no figures, v2: eq. (5.1) and related appendices corrected,
v3: final version to appear in JHE
Winding Number in String Field Theory
Motivated by the similarity between cubic string field theory (CSFT) and the
Chern-Simons theory in three dimensions, we study the possibility of
interpreting N=(\pi^2/3)\int(U Q_B U^{-1})^3 as a kind of winding number in
CSFT taking quantized values. In particular, we focus on the expression of N as
the integration of a BRST-exact quantity, N=\int Q_B A, which vanishes
identically in naive treatments. For realizing non-trivial N, we need a
regularization for divergences from the zero eigenvalue of the operator K in
the KBc algebra. This regularization must at same time violate the
BRST-exactness of the integrand of N. By adopting the regularization of
shifting K by a positive infinitesimal, we obtain the desired value
N[(U_tv)^{\pm 1}]=\mp 1 for U_tv corresponding to the tachyon vacuum. However,
we find that N[(U_tv)^{\pm 2}] differs from \mp 2, the value expected from the
additive law of N. This result may be understood from the fact that \Psi=U Q_B
U^{-1} with U=(U_tv)^{\pm 2} does not satisfy the CSFT EOM in the strong sense
and hence is not truly a pure-gauge in our regularization.Comment: 20 pages, no figures; v2: references added, minor change
Open String on Symmetric Product
We develop some basic properties of the open string on the symmetric product
which is supposed to describe the open string field theory in discrete
lightcone quantization (DLCQ). After preparing the consistency conditions of
the twisted boundary conditions for Annulus/M\"obius/Klein Bottle amplitudes in
generic non-abelian orbifold, we classify the most general solutions of the
constraints when the discrete group is . We calculate the corresponding
orbifold amplitudes from two viewpoints -- from the boundary state formalism
and from the trace over the open string Hilbert space. It is shown that the
topology of the world sheet for the short string and that of the long string in
general do not coincide. For example the annulus sector for the short string
contains all the sectors (torus, annulus, Klein bottle, M\"obius strip) of the
long strings. The boundary/cross-cap states of the short strings are classified
into three categories in terms of the long string, the ordinary boundary and
the cross-cap states, and the ``joint'' state which describes the connection of
two short strings. We show that the sum of the all possible boundary conditions
is equal to the exponential of the sum of the irreducible amplitude -- one body
amplitude of long open (closed) strings. This is typical structure of DLCQ
partition function. We examined that the tadpole cancellation condition in our
language and derived the well-known gauge group .Comment: 56 pages, 11 figures, Late
Stochastic Hamiltonian for Non-Critical String Field Theories from Double-Scaled Matrix Models
We present detailed discussions on the stochastic Hamiltonians for
non-critical string field theories on the basis of matrix models. Beginning
from the simplest case, we derive the explicit forms of the Hamiltonians
for the higher critical case (which corresponds to ) and for the
case , directly from the double-scaled matrix models. In particular, for
the two-matrix case, we do not put any restrictions on the spin configurations
of the string fields. The properties of the resulting infinite algebras of
Schwinger-Dyson operators associated with the Hamiltonians and the derivation
of the Virasoro and algebras therefrom are also investigated. Our results
suggest certain universal structure of the stochastic Hamiltonians, which might
be useful for an attempt towards a background independent string field theory.Comment: 70 pages, LaTeX, typographical errors are corrected, to be published
in Phys. Rev.
Vacuum oscillations and excess of high energy solar neutrino events observed in Superkamiokande
The excess of solar-neutrino events above 13 MeV that has been recently
observed by Superkamiokande can be explained by the vacuum oscillation solution
to the Solar Neutrino Problem (SNP). If the boron neutrino flux is 20% smaller
than the standard solar model (SSM) prediction and the chlorine signal is
assumed 30% (or 3.4 sigmas) higher than the measured one, there exists a vacuum
oscillation solution to SNP that reproduces both the observed spectrum of the
recoil electrons, including the high energy distortion, and the other measured
neutrino rates. The most distinct signature of this solution is a semi-annual
seasonal variation of the Be7 neutrino flux with maximal amplitude. While the
temporal series of the GALLEX and Homestake signals suggest that such a
seasonal variation could be present, future detectors (BOREXINO, LENS and
probably GNO) will be able to test it.Comment: ReVTeX, 8 pages, 7 figures included using psfig.sty ; references and
notes adde
JHK Spectra of the z=2.39 Radio Galaxy 53W002
We present low-resolution, near-IR JHK spectra of the weak z=2.39 radio
galaxy 53W002, obtained with the OH-airglow Suppressor spectrograph (OHS) and
Cooled Infrared Spectrograph and Camera for OHS (CISCO) on the Subaru
Telescope. They cover rest-frame wavelengths of 3400-7200 A, and the emission
lines of [O II]3727, Hb, [O III]4959, 5007, Ha, [N II]6548, 6583 and [S
II]6716, 6731 were detected. Using the Ha/Hb line ratio, we find an extinction
of E(B-V)=0.14. The emission-line ratios are reproduced by a cloud of electron
density n_e=1x10^{3-4}(/cm3) with solar metallicity, ionized by an alpha=-0.7
power-law continuum with ionizing parameter U=1x10^-3. In addition to these
emission lines, we make the first spectroscopic confirmation of the Balmer
discontinuity in a high-z radio galaxy. Together with rest-frame UV photometry
from the literature, we show that at least 1/3 of the present stellar mass was
formed in the current starburst. The stellar mass was estimated to be
(1-1.4)x10^11 M_sol by one-component model fitting, which is smaller than that
of typical z~1 B2/6C radio galaxies. We suggest that 53W002 is currently
assembling a large part of its stellar mass through merger events with the
surrounding sub-galactic clumps, some of which can be identified with the Lya
emitters detected in narrow-band imaging. After a few such events over the next
few Gyr, 53W002 will evolve into a massive elliptical galaxy.Comment: 10 pages, including 11 figures. Accepted for publication in
PASJ(2001). Revised 5/15/200
- …