3,590 research outputs found
Torsional Newton-Cartan Geometry from the Noether Procedure
We apply the Noether procedure for gauging space-time symmetries to theories
with Galilean symmetries, analyzing both massless and massive (Bargmann)
realizations. It is shown that at the linearized level the Noether procedure
gives rise to (linearized) torsional Newton-Cartan geometry. In the case of
Bargmann theories the Newton-Cartan form couples to the conserved mass
current. We show that even in the case of theories with massless Galilean
symmetries it is necessary to introduce the form and that it couples to
a topological current. Further, we show that the Noether procedure naturally
gives rise to a distinguished affine (Christoffel type) connection that is
linear in and torsionful. As an application of these techniques we
study the coupling of Galilean electrodynamics to TNC geometry at the
linearized level.Comment: 31 pages; v2 references adde
Wi-Fi password stealing program using USB rubber ducky
A minute is all it takes for a hacker to gain informations from your computer, such as Wi-Fi password. Due to the limited capability of people to remember a lot of complex and unique password, people tend to use the same password for most of their account. This paper aimed to implement Wi-Fi password stealing program in USB Rubber Ducky using USB Rubber Ducky Scripting, Visual Basic Script, Web Server, Command Prompt, and Ducky Toolkit to obtain clear text Wi-Fi password that ever connected to the computer. In the testing phase, the success rate of Wi-Fi password stealing program reached 94.28% with 87.87% obtained personal password is still categorized as guessable password and the password reuse rate reached 81.81%. Thus, Wi-Fi password stealing program can be very dangerous as most of the personal password was used in lots of account and still categorized as guessable
Probability Density of the Multipole Vectors for a Gaussian Cosmic Microwave Background
We review Maxwell's multipole vectors, and elucidate some of their
mathematical properties, with emphasis on the application of this tool to the
cosmic microwave background (CMB). In particular, for a completely random
function on the sphere (corresponding to the statistically isotropic Gaussian
model of the CMB), we derive the full probability density function of the
multipole vectors. This function is used to analyze the internal configurations
of the third-year Wilkinson Microwave Anisotropy Probe quadrupole and octopole,
and we show the observations are consistent with the Gaussian prediction. A
particular aspect is the planarity of the octopole, which we find not to be
anomalous.Comment: 12 pages, 7 figures, MNRAS styl
Gully Control on the Sumter National Forest in S.C.
2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio
Gravity between Newton and Einstein
Statements about relativistic effects are often subtle. In this essay we will
demonstrate that the three classical tests of general relativity, namely
perihelion precession, deflection of light and gravitational redshift, are
passed perfectly by an extension of Newtonian gravity that includes
gravitational time dilation effects while retaining a non-relativistic causal
structure. This non-relativistic gravity theory arises from a covariant large
speed of light expansion of Einstein's theory of gravity that does not assume
weak fields and which admits an action principle.Comment: Essay written for the Gravity Research Foundation 2019 Awards for
Essays on Gravitation; Honorable Mentio
Limited memory switched Broyden method for faster image deblurring
Iterative methods have gained a solid reputation for efficient image restoration, for both spatially invariant and spatially variant blurs. This paper shows how a "strap-on" quasi-Newton Broyden method can further accelerate the convergence of these iterative methods with little extra overhead
\u27Invisible Whispering\u27: Instant Messaging in Meetings
We use Goffman’s characterization of front and backstage interaction practices to analyze how the use of instant messaging in both face-to-face and technology-mediated meetings alters the spatial, temporal, and social configurations of meetings. In an interview study of workers in two organizations, we found that workers used instant messaging during face-to-face meetings and telephone conference calls (1) to participate concurrently in front and backstage interactions, (2) to participate in multiple, concurrent, backstage conversations, and (3) to manage and influence front stage activities through concurrent backstage conversations. These interactions would be either physically impossible or socially constrained without the use of instant messaging. We draw on psychology, GSS, and communication studies to consider the implications for group work
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