M2-M5 Systems in N=6 Chern-Simons Theory

We study two aspects of M5-branes in N=6 U(N)xU(N) Chern-Simons gauge theory. We first examine multiple M2-branes ending on a M5-brane. We study Basu-Harvey type cubic equations, fuzzy funnel configurations, and derive the M5-brane tension from the N=6 theory. We also find a limit in which the above M2-M5 system reduces to a D2-D4 system and we recover the Nahm equation from the N=6 theory. We then examine domain wall configurations in mass-deformed N=6 theory with a manifest SU(2)xSU(2)xU(1) global symmetry. We derive tensions of domain walls connecting between arbitrary M5-brane vacua of the deformed theory and observe their consistency with gravity dual expectations.Comment: 15 pages, Latex. v2: typos fixed, reference added. v3: Journal version in JHE

Light Gauginos and Conformal Sequestering

In a wide class of direct and semi-direct gauge mediation models, it has been observed that the gaugino masses vanish at leading order. It implies that there is a hierarchy between the gaugino and sfermion masses, invoking a fine-tuning problem in the Higgs sector via radiative corrections. In this paper, we explore the possibility of solving this anomalously light gaugino problem exploiting strong conformal dynamics in the hidden sector. With a mild assumption on the anomalous dimensions of the hidden sector operators, we show that the next to leading order contributions to the gaugino masses can naturally be in the same order as the sfermion masses. \mu/B_\mu problem is also discussed.Comment: 17 pages, 1 figure. References adde

Five-Dimensional Gauged Supergravity with Higher Derivatives.

This thesis summarizes the recent developments on the study of five-dimensional gauged supergravity with higher derivative terms, emphasizing in particular the ap- plication to understanding the hydrodynamic properties of gauge theory plasma via the AdS/CFT correspondence. We first review how the ungauged and gauged five- dimensional supergravity actions with higher derivative terms can be constructed using the off-shell superconformal formalism. Then we relate the gauged supergrav- ity to four-dimensional gauge theory using the AdS/CFT correspondence and extract the physical quantities associated with gauge theory plasma from the dual classical supergravity computations. We put a particular emphasis on the discussion of the conjectured lower bound for the shear viscosity over entropy density ratio proposed by Kovtun, Son and Starinets, and discuss how higher derivative terms in supergrav- ity and the introduction of chemical potential for the R-charge affect this bound.PHDPhysicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/93983/1/hanaki_1.pd

Temporal Analysis of Language through Neural Language Models

We provide a method for automatically detecting change in language across time through a chronologically trained neural language model. We train the model on the Google Books Ngram corpus to obtain word vector representations specific to each year, and identify words that have changed significantly from 1900 to 2009. The model identifies words such as "cell" and "gay" as having changed during that time period. The model simultaneously identifies the specific years during which such words underwent change

Black holes in five-dimensional gauged supergravity with higher derivatives

We examine five-dimensional $\mathcal N=2$ gauged supergravity including terms up to four derivatives. These additional terms correspond to the supersymmetric completion of $R^2$, and were originally obtained in hep-th/0611329 using conformal supergravity techniques. Here we integrate out the auxiliary fields and obtain the on-shell action for minimal supergravity with such corrections. We then construct $R$-charged AdS black holes to linear order in the four derivative terms and investigate the effect of these corrections on their thermodynamical properties. Finally, we relate the geometrical coefficients governing the four-derivative corrections to gauge theory data using holographic anomaly matching. This enables us to obtain a microscopic expression for the entropy of the solutions.Comment: 34 pages. Typos fixed, some comments and references adde

Higher derivative effects on eta/s at finite chemical potential

We examine the effects of higher derivative corrections on eta/s, the ratio of shear viscosity to entropy density, in the case of a finite R-charge chemical potential. In particular, we work in the framework of five-dimensional N =2 gauged supergravity, and include terms up to four derivatives, representing the supersymmetric completion of the Chern-Simons term A \wedge Tr (R \wedge R). The addition of the four-derivative terms yields a correction which is a 1/N effect, and in general gives rise to a violation of the eta/s bound. Furthermore, we find that, once the bound is violated, turning on the chemical potential only leads to an even larger violation of the bound.Comment: Typos fixed, references and comments on conventions adde

Comments on Charges and Near-Horizon Data of Black Rings

We study how the charges of the black rings measured at the asymptotic infinity are encoded in the near-horizon metric and gauge potentials, independent of the detailed structure of the connecting region. Our analysis clarifies how different sets of four-dimensional charges can be assigned to a single five-dimensional object under the Kaluza-Klein reduction. Possible choices are related by the Witten effect on dyons and by the large gauge transformation in four and five dimensions, respectively.Comment: 30 pages, 1 figure; v2: additional references; v3: published versio

Symmetries of Holographic Super-Minimal Models

We compute the asymptotic symmetry of the higher-spin supergravity theory in AdS_3 and obtain an infinite-dimensional non-linear superalgebra, which we call the super-W_infinity[lambda] algebra. According to the recently proposed supersymmetric duality between higher-spin supergravity in an AdS_3 background and the 't Hooft limit of the N=2 CP^n Kazama-Suzuki model on the boundary, this symmetry algebra should agree with the 't Hooft limit of the chiral algebra of the CFT, SW_n. We provide two nontrivial checks of the duality. By comparing the algebras, we explicitly match the lowest-spin commutation relations in the super-W_infinity[lambda] with the corresponding commutation relations in the 't Hooft limit on the CFT side. We also consider the degenerate representations of the two algebras and find that the spectra of the chiral primary fields are identical.Comment: 33 pages, references added, some errors corrected, discussions about the truncation of the shs[lambda] algebra and reobtaining the original shs[lambda] algebra from the super-W_infinity[lambda] algebra adde