On Chiral Mesons in AdS/CFT

We analyze the spectra of non-chiral and chiral bifundamental mesons arising on intersecting D7-branes in $AdS_{5}\times S^{5}$. In the absence of magnetic flux on the curve of intersection, the spectrum is non-chiral, and the dual gauge theory is conformal in the quenched/probe approximation. For this case we calculate the dimensions of the bifundamental mesonic operators. We then consider magnetization of the D7-branes, which deforms the dual theory by an irrelevant operator and renders the mesons chiral. The magnetic flux spoils the conformality of the dual theory, and induces a D3-brane charge that becomes large in the ultraviolet, where the non-normalizable bifundamental modes are rapidly divergent. An ultraviolet completion is therefore necessary to calculate the correlation functions in the chiral case. On the other hand, the normalizable modes are very well localized in the infrared, leading to new possibilities for local model-building on intersecting D7-branes in warped geometries.Comment: 32 pages, 4 figure

Pynchon and Place: A Geocritical Reading of Thomas Pynchon

A special emphasis on artificial or constructed spaces appears throughout Thomas Pynchon’s body of work. This thesis explores how Pynchon describes such spaces and their uses to address such weighty topics as social inequity and the struggle against authoritarianism. In examining the role of sheltering spaces in novels such as V. and Gravity’s Rainbow, I argue that Pynchon depicts various “outsider” characters as finding reification of their own forms of alterity within spaces either designed or co-opted with such purpose in mind. Through Pynchon’s depiction of spatial transformation in novels like Vineland and Inherent Vice, the author finds the opportunity to address ethical issues revolving around concepts of real estate and private property, such as gentrification. Even graphical depictions of space, such as the maps of Mason & Dixon or virtual reality program found in Bleeding Edge, present themselves as worthy figures of study in Pynchon’s work, as representations of space that seek to establish boundaries or delineated property play an integral role in the authoritarian forces that seek to oppress the downtrodden, or those whom society views as “the Other.” A geocritical reading of Thomas Pynchon’s work not only provides readers with a clearer understanding of the political thought guiding the author’s pen, but also provides his readers with a means of navigating his sometimesencyclopedic novels

Compact Scalars at the Cosmological Collider

We study the dynamics of scalar fields with compact field spaces, or axions, in de Sitter space. We argue that the field space topology can qualitatively affect the physics of these fields beyond just which terms are allowed in their actions. We argue that the sharpest difference is for massless fields -- the free massless noncompact scalar field does not admit a two-point function that is both de Sitter-invariant and well-behaved at long distances, while the massless compact scalar does. As proof that this difference can be observable, we show that the long-distance behavior of a heavy scalar field, and thus its cosmological collider signal, can qualitatively change depending on whether it interacts with a light compact or noncompact scalar field. We find an interesting interplay between the circumference of the field space and the Hubble scale. When the field space is much larger than Hubble, the compact field behaves similarly to a light noncompact field and forces the heavy field to dilute much faster than any free field can. However, depending on how much smaller the field space is compared to Hubble, the compact field can cause the heavy scalar to decay either faster or slower than any free field and so we conclude that there can be qualitative and observable consequences of the field space's topology in inflationary correlation functions.Comment: 40+10 pages, 4 figures, many diagram

Processing of Song Signals in the Cricket and its Hormonal Control

SYNOPSIS. Phonotaxis by female crickets to the calling song of males, is an important model for investigating the neural basis of auditory behavior. Recent advances make it possible to explain some components of this behavior and its hormonal control, at the level of identified neurons and molecular expression within those neurons. Tonotopically arranged afferents from the cricket\u27s ear, project to local and intersegmental prothoracic interneurons. Bilateral processing of signals and some temporal-pattern specific processing occurs in the prothoracic ganglion and influences acoustic information that is sent to the brain via ascending interneurons that are demonstrably involved in phonotaxis. High, low and band- pass interneurons in the brain continue temporal pattern processing which matches the selectivity of phonotaxis and may be filters for recognition of the calling song. Neurons descending from the brain and prothoracic ganglion, direct multimodal signals (including auditory) to more posterior regions, possibly the leg motor neurons that are responsible for phonotaxis. Age-related changes or artificially induced changes in Juvenile Hormone III levels regulate the threshold for phonotaxis in Acheta domesticus, by varying the threshold of LI, a prothoracic ascending interneuron that is necessary for phonotaxis to low intensity calling songs. Results from in situ hybridization suggest that this might be accomplished, in part, by controlling the levels of nicotinic acetylcholine receptor-like mRNA expressed in LI, presumably by increasing its neurotransmitter receptor density. L3 is a prothoracic ascending interneuron that exhibits bandselective response properties to the syllable period of the calling song. L3\u27s response is age and JHIII related, and is correlated to phonotactic selectivity. These changes in L3 might be accomplished, at least in part by JHIII regulating the expression of nicotinic acetylcholine receptor-like mRNA in L3 ©1994 American Society of Zoologists