Transverse effects in multifrequency Raman generation

The theory of ultrabroadband multifrequency Raman generation is extended, for the first time, to allow for beam-propagation effects in one and two transverse dimensions. We show that a complex transverse structure develops even when diffraction is neglected. In the general case, we examine how the ultrabroadband multifrequency Raman generation process is affected by the intensity, phase quality, and width of the input beams, and by the length of the Raman medium. The evolution of power spectra, intensity profiles, and global characteristics of the multifrequency beams are investigated and explained. In the two-dimensional transverse case, bandwidths comparable to the optical carrier frequency, spanning the whole visible spectrum and beyond, are still achievable

Ultrabroad-bandwidth multifrequency Raman soliton pulse trains

I have discovered that in the coherent regime of ultrabroad-bandwidth Raman generation, a large number of long-lived soliton pulse trains are spontaneously generated. This novel solution of the dispersionless and highly transient regime, involving more than 40 distinct Raman lines of comparable amplitude, is found to be a strong attractor in the nonlinear dynamics, even when the system is initially far from this limit

Renormalization group computation of likelihood functions for cosmological data sets

I show how a renormalization group (RG) method can be used to incrementally integrate the information in cosmological large-scale structure data sets (including CMB, galaxy redshift surveys, etc.). I show numerical tests for Gaussian fields, where the method allows arbitrarily close to exact computation of the likelihood function in order $\sim N$ time, even for problems with no symmetry, compared to $N^3$ for brute force linear algebra (where $N$ is the number of data points -- to be fair, methods already exist to solve the Gaussian problem in at worst $N \log N$ time, and this method will not necessarily be faster in practice). The method requires no sampling or other Monte Carlo (random) element. Non-linearity/non-Gaussianity can be accounted for to the extent that terms generated by integrating out small scale modes can be projected onto a sufficient basis, e.g., at least in the sufficiently perturbative regime. The formulas to evaluate are straightforward and require no understanding of quantum field theory, but this paper may also serve as a pedagogical introduction to Wilsonian RG for astronomers.Comment: 13 pg, 4 fi

Synchronous Online Philosophy Courses: An Experiment in Progress

There are two main ways to teach a course online: synchronously or asynchronously. In an asynchronous course, students can log on at their convenience and do the course work. In a synchronous course, there is a requirement that all students be online at specific times, to allow for a shared course environment. In this article, the author discusses the strengths and weaknesses of synchronous online learning for the teaching of undergraduate philosophy courses. The author discusses specific strategies and technologies he uses in the teaching of online philosophy courses. In particular, the author discusses how he uses videoconferencing to create a classroom-like environment in an online class

Comment on Vacuum Stability and Electroweak Baryogenesis in the MSSM with Light Stops

We show that, for all values of $Tan \beta$ and the light right-handed stop mass for which the electroweak phase transition is strong enough to avoid washout following electroweak baryogenesis, the electroweak vacuum is stable over the lifetime of the observed Universe. Cosmological stability of the electroweak vacuum is violated only if the light right-handed stop is lighter than 100-115GeV.Comment: LaTex, 11 pages, no figures. Additions to text and reference

Unparticles: Interpretation and Cosmology.

We discuss the physical interpretation of unparticles and review the constraints from cosmology. Unparticles may be understood in terms of confined states of a strongly-coupled scale-invariant theory, where scale-invariance implies that the confined states have continuous masses. This picture is consistent with the observation that unparticle operators can be represented in terms of continuous mass fields. Finite results in scattering processes are obtained by compensating the infinite number of unparticle final states with an infinitesimal coupling per unparticle. As a result, unparticles are stable with respect to decay or annihilation to Standard Model particles, implying a one-way flow of energy from the Standard Model sector to the unparticle sector. The qualitative properties of unparticles, which result from their continuous mass nature, are unchanged in the case where scale-invariance is broken by a mass gap. Unparticles with a mass gap can evade constraints from astrophysical and 5th force considerations, in which case cosmology provides the strongest constraints

Local and Minority Hiring Practices

This brief discusses various strategies to ensure a diverse and local workforce at the Canal Side project on Buffalo’s waterfront. To make the project as advantageous to the community as possible requires the use of exact language in contracts governing the development, active participation of local neighborhoods, a monitoring system to track efforts made by developers and jobseekers and then distribute the results to the community, and civic oversight to hold the businesses accountable and oversee the program for effectiveness. Canal Side plans to offer over 1 million square feet of space as a shopping district, hotel, and entertainment center, including a Bass Pro shop. The agency developing it promises, among other things, the addition of 1,000 new jobs, $9.5 million in annual sales, and the replacement and renovation of Memorial Auditorium and the Donovan building