PeV scale Supersymmetry breaking and the IceCube neutrino flux

The observation of very high energy neutrino events at IceCube has grasped a lot of attention in the fields of both astrophysics and particle physics. It has been speculated that these high energy neutrinos might originate either from purely conventional astrophysical sources or from the late decay of a super heavy (PeV scale) dark matter (DM) particle. In order for decaying DM to be a dominant source of the IceCube high-energy neutrinos, it would require an unusually suppressed value of the coupling of DM to neutrinos. We attempt to explain this small coupling in the context of an $R$-parity conserving minimal supergravity model which has right-handed neutrino superfields. With the main assumptions of super-partner masses at the PeV scale and also a reheating temperature not much larger than the PeV scale, we find in our model several natural order-of-magnitude "miracles", (i) the gravitino is produced via freeze-in as a DM candidate with the correct relic density (ii) the right-handed (RH) sneutrino makes up only a tiny fraction ($10^{-6})$, of the present day energy density of the universe, yet its decay lifetime to the gravitino and neutrinos is such that it naturally predicts the right order-of-magnitude for the IceCube neutrino flux. The long lifetime of the RH sneutrino is explained by the existence of a global $R$-symmetry which is only broken due to supersymmetry breaking effects. Our model also predicts a flux of 100 TeV gamma rays from the decaying RH sneutrino which are within the current observational constraints.Comment: v2: 34 pages, 6 figures, Journal version (published in JHEP

Transport Coefficients of Black MQGP M3-Branes

The SYZ mirror, in the `delocalized limit' of [1], of (M)N (fractional)D3-branes, and wrapped N_f flavor D7-branes in the presence of a black-hole resulting in a non-Kaehler resolved warped deformed conifold (NKRWDC) in [2], was carried out in [3] and resulted in black M3-branes. The uplift, if valid globally(like [4] for fractional D3 branes in conifolds), asymptotes to M5-branes wrapping a two-cycle (homologously an (large) integer sum of two-spheres) in AdS_5xM_6. Interestingly, in the MQGP limit, assuming the deformation > resolution, by estimating the five SU(3) structure torsion (\tau) classes W_{1,2,3,4,5} we show that \tau\in W_4+W_5: 2/3 Re(W^3bar_5)=W^3bar_4 in the UV, implying the NKRWDC locally preserves SUSY. Further, the local T^3 of [3] in the large-r limit and the `MQGP' limit of [3], satisfies the same conditions as the maximal T^2-invariant special Lagrangian three-cycle of T^*(S^3) of [6], partly justifying use of local SYZ mirror symmetry in [3]. Using the Ouyang embedding in the DBI action of a D7-brane or by dimensionally reducing the 11-dimensional EH action to five (R^{1,3},r) dimensions, we then calculate a variety of gauge and metric-perturbation-modes' two-point functions using the prescription of [5], and show: (i) diffusion constant D~1/T, (ii) the electrical conductivity \sigma~T, (iii) the charge susceptibility \chi~ T^2, (iv) [using (i) - (iii)] the Einstein's relation \sigma/\chi=D, is indeed satisfied, (v) the R-charge diffusion constant D_R~1/T, and (vi) the possibility of generating \eta/s=1/4pi from solutions to the vector and tensor mode metric perturbations' EOMs, separately. All results are also valid in the limit of [2].Comment: v4:1+50 pages, correction in torsion classes: type IIB, locally, has SUSY in the U

Anti-HIV therapy: pipeline approaches and future directions

Human immunodeficiency virus (HIV), with about 30 million deaths and double infections (in developing countries), is an open challenge today for global scientists. Developing safe and effective measurements against it has become the prime need of hour. Though, putting it at health priority, various efforts like chemotherapy, vaccines and others are attempted globally over last decade. Consequently, highly active antiretroviral therapy was introduced but fails to completely block the viral replication due to drug resistance and various other severe side effects. The antigenic variability and lack of appropriate experimental models is the major obstacle in the development of an ever effective treatment against HIV. However, to overcome the present hurdles and to emerge a preventive HIV vaccine efforts at various platforms are done. A renewed, coordinated research, preclinical studies, clinical trials together with sufficient long term scientific and commercial commitments are made. Few of the therapeutic efforts viz. RNA interference (RNAi) based replication arrest of HIV, viral enzymes’ inhibitors, nanotechnology based HIV control and various preclinically trialed vaccines are reviewed in this paper. Also, the observed toxicity of existing therapeutic regimen, key challenges and future prospects for the development of better tolerated prophylactic HIV-1 vaccine are discussed

Towards MQGP

For the Ouyang embedding we calculate the chemical potential mu_C due to a U(1) gauge field on the w.v. of N_f D7-branes wrapped around a 4-cycle in a resolved warped deformed conifold with (M)N (fractional)D3-branes of [1], and show the possible thermodynamical stability up to linear order in the embedding parameter. In the spirit of [2] we obtain the local type IIA mirror using SYZ mirror symmetry near (theta_{1,2},psi)=(,{0,2pi,,4pi}) and then oxidize the same to M theory. We take two limits of this uplift:(i)g_s,g_sN_f,g_sM^2/N,g_s^2M N_f>1 similar to [1] effected by M eps^{-3d/2}, N eps^{-19d},g_s epsn^d,d>0 and eps<=O(0.01);(ii)the `MQGP limit' g_sM^2/N>1 for finite g_s,M, effected by: g_s eps, M eps^{-3d/2},N eps^{-39d},d>0, eps<~1). The second limit is more suited for the study of QGP (See [3]) and can only be addressed in M theory. The uplift gives a black M3-brane solution whose near-horizon geometry near theta_{1,2}=0,pi-branches, preserves 1/8 SUSY. We obtain eta/s=1/4pi for the uplift and the diffusion constant for types IIB/IIA backgrounds comes out to be ~1/T, for both limits. The D=11 SUGRA action up to O(R^4,|G_4|^2) is expected to receive dominant contributions near =0,pi due to poles. Introducing a small-angle cut-off c and using the =c,(pi-c)-local uplift the specific heat from the IR-finite part of the action (c-independent) turns out to be positive indicative of the thermodynamical stability of the uplift. An ALD-gravity-type interpretation can be given to the counter-terms for(i). Its verified that the black M3-brane entropy S r_h^3 from M-theoretic thermodynamical methods and the horizon areas of types IIB/IIA/M3-brane solutions.Comment: 1+58 pages, LaTeX; v4 some minor corrections, results unchange

A Review on Audio Cryptography

Volume 3 Issue 7 (July 2015

On Discovering Electromagnetic Emission from Neutron Star Mergers: The Early Years of Two Gravitational Wave Detectors

We present the first simulation addressing the prospects of finding an electromagnetic (EM) counterpart to gravitational wave detections (GW) during the early years of only two advanced interferometers. The perils of such a search may have appeared insurmountable when considering the coarse ring-shaped GW localizations spanning thousands of deg^2 using time-of-arrival information alone. We show that leveraging the amplitude and phase information of the predicted GW signal narrows the localization to arcs with a median area of only ~250 deg^2, thereby making an EM search tractable. Based on the locations and orientations of the two LIGO detectors, we find that the GW sensitivity is limited to one polarization and thus to only two sky quadrants. Thus, the rates of GW events with two interferometers is only ~40% of the rate with three interferometers of similar sensitivity. Another important implication of the sky quadrant bias is that EM observatories in North America and Southern Africa would be able to systematically respond to GW triggers several hours sooner than Russia and Chile. Given the larger sky areas and the relative proximity of detected mergers, 1m-class telescopes with very wide-field cameras are well positioned for the challenge of finding an EM counterpart. Identification of the EM counterpart amidst the even larger numbers of false positives further underscores the importance of building a comprehensive catalog of foreground stellar sources, background AGN and potential host galaxies in the local universe.Comment: Submitted to ApJL, 8 pages, 4 figures, 1 tabl

Phosphoproteomic Characterization Of Glycogen Synthase Kinase-3

Glycogen Synthase Kinase-3 (GSK-3) is a constitutively active, ubiquitously expressed kinase that acts as a critical regulator of many signaling pathways. These pathways, when dysregulated, have been implicated in many human diseases, including bipolar disorder (BD), cancer, and diabetes. Over 100 putative GSK-3 substrates have been reported, based on direct kinase assays or genetic and pharmacological manipulation of GSK-3, in diverse cell types. Many more have been predicted based upon on the prevalence of the GSK-3 consensus sequence. As a result, there remains an unclear picture of the complete GSK-3 phosphoproteome. We have therefore used a large-scale mass spectrometry approach to analyze global changes in phosphorylation and describe the repertoire of GSK-3 substrates in a single cell type. For our studies, we used stable isotope labeling of amino acids in culture (SILAC) to compare the phosphoproteome of wild-type mouse embryonic stem cells (ESCs) to ESCs completely lacking Gsk3a and Gsk3b expression (Gsk3 DKO). We used titanium oxide chromatography to enrich for phosphorylated peptides. From our analysis, we selected 65 phosphoproteins that exhibited significantly reduced phosphorylation in Gsk3 DKO ESCs as high-confidence candidate substrates of GSK-3. Our findings indicate that these candidate GSK-3 substrates can influence all levels of gene expression including chromatin modulators, transcription factors, RNA binding proteins, splicing factors, translational initiators and cell cycle regulators. Analysis of protein-protein interaction networks revealed enrichment of a cluster of proteins involved in alternative splicing. Our study is the first to discover a function for GSK-3 in alternative splicing. To further validate our top hits, we conducted in vitro kinase assays with recombinant proteins and identified the splicing factor RBM8A and an RNA processing protein NPM1 to be direct targets of GSK-3. Preliminary RNA sequencing results point to an overall increase in alternative splicing events when Gsk3 is deleted. Taken together, the research in this dissertation represents the first unbiased analysis of GSK-3 phosphorylation substrates in a single cell type and provides the first evidence of GSK-3 as a general regulator of alternative splicing