Schr\"odinger Deformations of AdS_3 x S^3

We study Schr\"odinger invariant deformations of the AdS_3 x S^3 x T^4 (or K3) solution of IIB supergravity and find a large class of solutions with integer and half-integer dynamical exponents. We analyze the supersymmetries preserved by our solutions and find an infinite number of solutions with four supersymmetries. We study the solutions holographically and find that the dual D1-D5 (or F1-NS5) CFT is deformed by irrelevant operators of spin one and two.Comment: 23 page

Holographic flows to IR Lifshitz spacetimes

Recently we studied `vanishing' horizon limits of `boosted' black D3-brane geometry \cite{hsnr}. The type IIB solutions obtained by taking these special double limits were found to describe nonrelativistic Lifshitz spacetimes at zero temperature. In the present work we study these limits for TsT black-hole solutions which include $B$-field. The new Galilean solutions describe a holographic RG flow from Schr\"odinger ($a=2$) spacetime in UV to a Lifshitz universe ($a=3$) in the IR.Comment: 10 pages; v2: A bad typo in eq.8 corrected; v3: Discussion and reference on Kaigorodov spaces included, correction in sec-3, to be published in JHE

Constructing Lifshitz solutions from AdS

Under general assumptions, we show that a gravitational theory in d+1 dimensions admitting an AdS solution can be reduced to a d-dimensional theory containing a Lifshitz solution with dynamical exponent z=2. Working in a d=4, N=2 supergravity setup, we prove that if the AdS background is N=2 supersymmetric, then the Lifshitz geometry preserves 1/4 of the supercharges, and we construct the corresponding Killing spinors. We illustrate these results in examples from supersymmetric consistent truncations of type IIB supergravity, enhancing the class of known 4-dimensional Lifshitz solutions of string theory. As a byproduct, we find a new AdS4 x S1 x T(1,1) solution of type IIB.Comment: 29 pages, no figures; v2 minor corrections, a reference adde

Lifshitz black holes in string theory

We provide the first black hole solutions with Lifshitz asymptotics found in string theory. These are expected to be dual to models enjoying anisotropic scale invariance with dynamical exponent z=2 at finite temperature. We employ a consistent truncation of type IIB supergravity to four dimensions with an arbitrary 5-dimensional Einstein manifold times a circle as internal geometry. New interesting features are found that significantly differ from previous results in phenomenological models. In particular, small black holes are shown to be thermodynamically unstable, analogously to the usual AdS-Schwarzschild black holes, and extremality is never reached. This signals a possible Hawking-Page like phase transition at low temperatures.Comment: 19 pages, 7 figures. v2 references adde

Universality and exactness of Schrodinger geometries in string and M-theory

We propose an organizing principle for classifying and constructing Schrodinger-invariant solutions within string theory and M-theory, based on the idea that such solutions represent nonlinear completions of linearized vector and graviton Kaluza-Klein excitations of AdS compactifications. A crucial simplification, derived from the symmetry of AdS, is that the nonlinearities appear only quadratically. Accordingly, every AdS vacuum admits infinite families of Schrodinger deformations parameterized by the dynamical exponent z. We exhibit the ease of finding these solutions by presenting three new constructions: two from M5 branes, both wrapped and extended, and one from the D1-D5 (and S-dual F1-NS5) system. From the boundary perspective, perturbing a CFT by a null vector operator can lead to nonzero beta-functions for spin-2 operators; however, symmetry restricts them to be at most quadratic in couplings. This point of view also allows us to easily prove nonrenormalization theorems: for any Sch(z) solution of two-derivative supergravity constructed in the above manner, z is uncorrected to all orders in higher derivative corrections if the deforming KK mode lies in a short multiplet of an AdS supergroup. Furthermore, we find infinite classes of 1/4 BPS solutions with 4-,5- and 7-dimensional Schrodinger symmetry that are exact.Comment: 31 pages, plus appendices; v2, minor corrections, added refs, slight change in interpretation in section 2.3, new Schrodinger and Lifshitz solutions included; v3, clarifications in sections 2 and 3 regarding existence of solutions and multi-trace operator

Holographic renormalization for irrelevant operators and multi-trace counterterms

We investigate the structure of holographic renormalization in the presence of sources for irrelevant operators. By working perturbatively in the sources we avoid issues related to the non-renormalizability of the dual field theory. We find new classes of divergences which appear to be non-local on the gravity side. However in all cases a systematic renormalization procedure exists involving either standard local counterterms or new counterterms which may be interpreted as multi-trace counterterms in the field theory. The multi-trace counterterms reflect a more intricate relation between sources and the asymptotics of bulk fields.Comment: 42 page

Irrelevant deformations and the holographic Callan-Symanzik equation

We discuss the systematics of obtaining the Callan-Symanzik equation within the framework of the gauge/gravity dualities. We present a completely general formula which in particular takes into account the new holographic renormalization results of arXiv:1102.2239. Non-trivial beta functions are obtained from new logarithmic terms in the radial expansion of the fields. The appearance of multi-trace counterterms is also discussed in detail and we show that mixing between single- and multi-trace operators leads to very specific non-linearities in the Callan-Symanzik equation. Additionally, we compute the conformal anomaly for a scalar three-point function in a CFT.Comment: 40 page

Recent updates and perspectives on approaches for the development of vaccines against visceral leishmaniasis

All rights reserved. Visceral leishmaniasis (VL) is one of the most important tropical diseases worldwide. Although chemotherapy has been widely used to treat this disease, problems related to the development of parasite resistance and side effects associated with the compounds used have been noted. Hence, alternative approaches for VL control are desirable. Some methods, such as vector control and culling of infected dogs, are insufficiently effective, with the latter not ethically recommended. The development of vaccines to prevent VL is a feasible and desirable measure for disease control, for example, some vaccines designed to protect dogs against VL have recently been brought to market. These vaccines are based on the combination of parasite fractions or recombinant proteins with adjuvants that are able to induce cellular immune responses, however, their partial efficacy and the absence of a vaccine to protect against human leishmaniasis underline the need for characterization of new vaccine candidates. This review presents recent advances in control measures for VL based on vaccine development, describing extensively studied antigens, as well as new antigenic proteins recently identified using immuno-proteomic techniquesThis work was supported by grants from Instituto Nacional de Ciência e Tecnologia em Nano-Biofarmacêutica, Rede Nanobiotec/Brasil-Universidade Federal de Uberlândia/CAPES, PRONEX-FAPEMIG (APQ-01019-09), FAPEMIG (CBB-APQ-00819-12 and CBB-APQ-01778-2014), and CNPq (APQ-482976/2012-8, APQ-488237/2013-0, and APQ-467640/2014-9). EAFC and LRG are recipients of the grant from CNPq. MACF is the recipient of grants from FAPEMIG/CAPE