D1 and D5-brane giant gravitons on AdS3×S3×S3×S1AdS_3 \times S^3 \times S^3 \times S^1

We construct various examples of 1/4-BPS giant gravitons embedded into the type IIB supergravity background $AdS_{3} \times S^{3}_{+} \times S^{3}_{-} \times S^{1}$ with pure R-R flux: two D1-brane giants wrapping 1-cycles in $AdS_{3}$ and $S^{3}_{+} \times S^{3}_{-}$, and one D5-brane giant wrapping a 4-cycle in $S^{3}_{+} \times S^{3}_{-}$ and the $S^{1}$. These D-branes are supported by angular momenta $\alpha$ P on one 3-sphere and $(1-\alpha)$ P on the other. We then construct a general class of 1/8-BPS D5-brane giant gravitons wrapping 4-cycles $\Sigma$ in $S^{3}_{+} \times S^{3}_{-}$ and the $S^{1}$. Here $\Sigma$ is the intersection of a holomorphic surface $\mathcal{C}$ in $\mathbb{C}^{2}_{+} \times \mathbb{C}^{2}_{-}$ with the $S^{3}_{+} \times S^{3}_{-}$ submanifold. The holomorphic surface $\mathcal{C}$ is defined by $f(y_{1}z_{1},y_{1}z_{2},y_{2}z_{1},y_{2}z_{2}) = 0$, with $y_{a}$ and $z_{a}$ the $\mathbb{C}^{2}_{\pm}$ complex coordinates. There is supersymmetry enhancement to 1/4-BPS in the special case $f(y_{1}z_{1}) = 0$ of which our original D5-brane giant graviton is an example.Comment: 30 pages, 4 figures. reference and figure added, minor change

Integrable open spin-chains in AdS3/CFT2 correspondences

We study integrable open boundary conditions for d(2,1;\alpha)^2 and psu(1,1|2)^2 spin-chains. Magnon excitations of these open spin-chains are mapped to massive excitations of type IIB open superstrings ending on D-branes in the AdS_3 x S^3 x S^3 x S^1 and AdS_3 x S^3 x T^4 supergravity geometries with pure R-R flux. We derive reflection matrix solutions of the boundary Yang-Baxter equation which intertwine representations of a variety of boundary coideal subalgebras of the bulk Hopf superalgebra. Many of these integrable boundaries are matched to D1- and D5-brane maximal giant gravitons.Comment: v1: 61 pages, 6 figures; v2: minor changes and reference added; v3: minor changes, 60 pages, version accepted to journa

A giant graviton genealogy

In this article we extend the construction of giant gravitons from holomorphic surfaces [arXiv:hep-th/0010206] to the ABJM correspondence. We construct a new class of 1/6-BPS M5-branes wrapping 5-manifolds in S^7/Z_k and supported by a large angular momentum in the orbifold space. These orbifold giant gravitons undergo a supersymmetry enhancement to 1/3-BPS and 1/2-BPS configurations in special cases. The compactification of M-theory on AdS_4 x S^7/Z_k to type IIA superstring theory on AdS_4 x CP^3 then gives rise to another new class of 1/6-BPS D4 and NS5-branes wrapping 4 and 5-manifolds in CP^3. The D4-branes carry a combination of D0-brane charge and angular momentum in the complex projective space, while the NS5-branes are supported only by D0-brane charge. Finally, we present a detailed analysis of a one-parameter family of 1/2-BPS M5-brane orbifold giant gravitons, and their D4 and NS5-brane CP^3 descendants.Comment: 34 pages; 1 figure; minor revisions; references adde

Meromorphic Functions and the Topology of Giant Gravitons

Using Mikhailov's map from holomorphic functions to supersymmetric D3-brane solutions, we show how to construct giant gravitons in AdS5 x S5 with toroidal topologies. In the 1/4-BPS sector we show that these are always of the form #^K (S2 x S1), and in the limit in which this becomes a set of m+n perpendicular spherical giants re-connected near to their intersections, we find K in terms of m,n. In the 1/8-BPS sector we find a similar class of solutions.Comment: 10 pages, 8 figure

S^2 x S^3 geometries in ABJM and giant gravitons

We construct a new NS5-brane solution in AdS_4 x CP^3 with S^2 x S^3 topology. This solution belongs to the general class of non-Einstein N_{11} metrics to which T^{1,1} belongs, and carries a non-vanishing D0-brane charge. In eleven dimensions it gives rise to a squashed S^2 x S^3 M5-brane giant graviton which is now of the N_{10} type. The energies of both solutions satisfy the BPS bound E=kQ/2, indicating supersymmetric configurations, where Q is interpreted as D0-brane charge for the NS5-brane and as angular momentum for the dynamically stable M5-brane giant graviton. The ground state is degenerate with a spherical D2 or M2-brane, rather than with a point-like object. Moreover, while the charge of the spherical 2-brane can be arbitrary, the charge of the S^2 x S^3 5-brane is bounded by N/2, with N the rank of the ABJM gauge group, a manifestation of the stringy exclusion principle. A microscopic description, suitable for the study of the finite 't Hooft coupling region, is provided in terms of spherical D2 or M2-branes expanding into fuzzy 3-spheres.Comment: 30 pages; 2 figures; change to JHEP3 style; minor revision

Susceptibility and synergism profiles of multi-drug resistant pseudomonas aeruginusa in an intensive care environment

Please read the abstract in the front section of this documentDissertation (MSc (Medical Microbiology))--University of Pretoria, 2005.Medical Microbiologyunrestricte

ADS/CFT correspondence in a non-supersymmetric Yi-deformed background

A non-supersymmetric Yi-deformed AdS/CFT correspondence has recently been conjectured by Frolov. A detailed description of both sides of this proposed gauge/string duality is presented. The analogy that exists between single trace gauge theory operators in the SU(3) sector and i-deformed SU(3) integrable spin chains is also discussed. Frolov, Roiban and Tseytlin’s leading order comparison between the ideformed spin chain coherent state action and i-deformed string worldsheet action in the semiclassical limit is reviewed. A particular Lax pair representation for the first order semiclassical i-deformed spin chain/string action is then constructed

Cancer diagnoses profile of bone marrow specimens from November 2012 to December 2015 in a tertiary academic setting

This study aimed to examine the number and type of cancer diagnoses made based on bone marrow aspirates (BMA) using morphology and/or histology, over a three year period. All the data collected (2012-2015) was obtained using the Trak-Care laboratory information system (LIS) of the National Health Laboratory Service (NHLS). Data was categorised into four categories including acute leukaemias (ALs), chronic leukaemias (CLs), Hodgkin’s lymphoma (HL), Non-Hodgkin’s lymphoma (NHL) and a miscellaneous group. The laboratory test most frequently used to make diagnoses was bone marrow aspiration (BMA) morphology (199), followed by flow cytometry (138), histology (113), fluorescent in situ hybridisation (FISH) (54) and polymerase chain reaction (PCR) (9). In total, the top three conditions diagnosed were acute myeloid leukaemias (AMLs), chronic myeloid leukaemia (CML) and B-cell acute lymphoblastic leukaemia (B-ALL). There was good agreement between the diagnoses made by BMA morphology, BMT histology and flow cytometry. Results showed that BMA morphology was the most popular diagnostic test used and that this test had excellent agreement with BMT histology and flow cytometry diagnoses. The most frequently diagnosed conditions were the AMLs.http://www.smltsa.org.za/publications.htmlam2018Haematolog