Perturbations in higher derivative gravity beyond maximally symmetric spacetimes

We study (covariant) scalar-vector-tensor (SVT) perturbations of infinite derivative gravity (IDG), at the quadratic level of the action, around conformally-flat, covariantly constant curvature backgrounds which are not maximally symmetric spacetimes (MSS). This extends a previous analysis of perturbations done around MSS, which were shown to be ghost-free. We motivate our choice of backgrounds which arise as solutions of IDG in the UV, avoiding big bang and black hole singularities. Contrary to MSS, in this paper we show that, generically, all SVT modes are coupled to each other at the quadratic level of the action. We consider simple examples of the full IDG action, and illustrate this mixing and also a case where the action can be diagonalized and ghost-free solutions constructed. Our study is widely applicable for both non-singular cosmology and black hole physics where backgrounds depart from MSS. In appendices, we provide SVT perturbations around conformally-flat and arbitrary backgrounds which can serve as a compendium of useful results when studying SVT perturbations of various higher derivative gravity models.Comment: 36 pages, 1 figur

Design and Realization of Fully-digital Microwave and Mm-wave Multi-beam Arrays with FPGA/RF-SOC Signal Processing

There has been a constant increase in data-traffic and device-connections in mobile wireless communications, which led the fifth generation (5G) implementations to exploit mm-wave bands at 24/28 GHz. The next-generation wireless access point (6G and beyond) will need to adopt large-scale transceiver arrays with a combination of multi-input-multi-output (MIMO) theory and fully digital multi-beam beamforming. The resulting high gain array factors will overcome the high path losses at mm-wave bands, and the simultaneous multi-beams will exploit the multi-directional channels due to multi-path effects and improve the signal-to-noise ratio. Such access points will be based on electronic systems which heavily depend on the integration of RF electronics with digital signal processing performed in Field programmable gate arrays (FPGA)/ RF-system-on-chip (SoC). This dissertation is directed towards the investigation and realization of fully-digital phased arrays that can produce wideband simultaneous multi-beams with FPGA or RF-SoC digital back-ends. The first proposed approach is a spatial bandpass (SBP) IIR filter-based beamformer, and is based on the concepts of space-time network resonance. A 2.4 GHz, 16-element array receiver, has been built for real-time experimental verification of this approach. The second and third approaches are respectively based on Discrete Fourier Transform (DFT) theory, and a lens plus focal planar array theory. Lens based approach is essentially an analog model of DFT. These two approaches are verified for a 28 GHz 800 MHz mm-wave implementation with RF-SoC as the digital back-end. It has been shown that for all proposed multibeam beamformer implementations, the measured beams are well aligned with those of the simulated. The proposed approaches differ in terms of their architectures, hardware complexity and costs, which will be discussed as this dissertation opens up. This dissertation also presents an application of multi-beam approaches for RF directional sensing applications to explore white spaces within the spatio-temporal spectral regions. A real-time directional sensing system is proposed to capture the white spaces within the 2.4 GHz Wi-Fi band. Further, this dissertation investigates the effect of electro-magnetic (EM) mutual coupling in antenna arrays on the real-time performance of fully-digital transceivers. Different algorithms are proposed to uncouple the mutual coupling in digital domain. The first one is based on finding the MC transfer function from the measured S-parameters of the antenna array and employing it in a Frost FIR filter in the beamforming backend. The second proposed method uses fast algorithms to realize the inverse of mutual coupling matrix via tridiagonal Toeplitz matrices having sparse factors. A 5.8 GHz 32-element array and 1-7 GHz 7-element tightly coupled dipole array (TCDA) have been employed to demonstrate the proof-of-concept of these algorithms

An Analytical Review of Privacy Preservation Using K Anonymity along with Bayesian Classifier in Data Mining

Privacy Preservation for social media is one of most trending research subject around the world. In addition to its trendiness, it is a very sensitive issue also. People around the world share their private information on the social media without thinking that it may affect their privacy. In such a condition it becomes the unrest duty to prevent the user information which is private. A lot of research workers have already put their ideas on table for the same issue. This paper studies the effect of Bayesian network in contrast to the prevention of the private data over social media. This paper also describes the pros and cons of using Bayesian Network for privacy preservation and also it compares some of the ethical prevention algorithms for the same. The evaluation has been done on the basis of ethical data mining parameters like Precision, Recall, F-Measur

Inflation candidates : from string theory to particles physics

Cosmic inflation is the cornerstone of modern cosmology. In particular, following the Planck mission reports presented in 2015 regarding cosmic microwave background (CMB), there is an increasing interest in searching for inflaton candidates within fundamental theories and to ultimately test them with future CMB data. This thesis presents inflationary models using a methodology that can be described as venturing top-down or bottom-up along energy scales. In the top-down motivation, we study inflationary scenarios in string theory and supergravity (SUGRA), namely with (multiple) 3-forms, Dirac-Born-Infeld Galileon model, a string field theory setup and N = 1 SUGRA attractor models. In the bottom-up motivation, we construct a grand unified theory based inflationary model with an additional conformal symmetry and study not only inflation but also provide predictions related to particle physics. Our research work includes various classes of inflation driven by scalar fields under a canonical, non-canonical and induced gravity frameworks. All these models are consistent with Planck data, supported by key primordial cosmological parameters such as the scalar spectral index ns, the tensor to scalar ratio r, together with the primordial non-Gaussianities. Future probes aiming to detect primordial gravitational waves and CMB non-Gaussianities can further help to distinguish between them.A inflação constitui um paradigma essencial na cosmologia moderna. Em particular, e de acordo com os comunicados da missão Planck em 2015, acerca da medição da radiação cósmica de fundo, há um interesse crescente na procura de candidatos a inflatão extraídos de teorias fundamentais e em testar estas propostas. Esta tese apresenta modelos inflacionários que podem ser classificados numa abordagem descendente ou ascendente nas escalas de energia. Na abordagem descendente, apresentamos estudos de cenários inflacionários ligados à teoria de cordas e à supergravidade (SUGRA), seja com campos (múltiplos) 3-formas, com o modelo Dirac-Born- Infeld Galileon, no contexto de uma teoria de campos para cordas ou ainda no modelo atrator SUGRA N = 1. Na abordagem ascendente, propomos a construção de um modelo inflacionário baseado numa teoria de grande unificação, complementada com uma simetria conforme, em que estudamos, não só a inflação, mas também implicações no campo da física de partículas. O nosso trabalho de investigação inclui diferentes classes de inflação governadas por campos escalares canónicos, não canónicos ou ainda em contexto de gravidade induzida. A totalidade destes modelos é consistente com os dados obtidos na missão Planck e suportados por parâmetros cosmológicos cruciais como o índice espectral escalar ns, a razão tensor para escalar r ou ainda a não-Gaussianidade primordial. O estudo abordado nesta tese reforça a espectativa que futuras missões observacionais, cujo objectivo seja detetar ondas gravitacionais primordiais e a não-Gaussianidade da radiação cósmica de fundo, possam ajudar a melhor distinguir os modelos inflacionários considerados

Macrophage COX-2 As a Target For Imaging And Therapy of Inflammatory Diseases Using Theranostic Nanoemulsions

Personalized medicine can be an approach to address the unsatisfactory treatment outcomes in inflammatory conditions such as cancer, arthritis, and cardiovascular diseases. A common feature of chronic diseases is the infiltration of pro-inflammatory macrophages at the disease loci. Infiltrating macrophages have been previously utilized for disease diagnosis. These features suggest that macrophages can be broadly applicable targets for simultaneous therapy and diagnosis. Cyclooxygenase-2 (COX-2), an enzyme involved in the biosynthesis of a lipid inflammatory mediator, prostaglandin E2 (PGE2), is over expressed in macrophages infiltrating the pathological site. Inhibition of PGE2 leads to reduced inflammation, pain and macrophage infiltration. To utilize macrophages for the purpose of simultaneous therapy and diagnosis, we proposed to integrate therapeutic and imaging capabilities on a single nanomedicine platform, referred as theranostics. A stable 19F MRI visible nanoemulsion platform was developed, incorporating celecoxib for COX-2 inhibition and near-infrared fluorescent dye(s) for fluorescence imaging. We hypothesized that inhibition of COX-2 in macrophages using a theranostic nanoemulsion will reduce the inflammation (and pain), and that this response can be visualized by monitoring changes in macrophage infiltration. In vitro characterization demonstrated that the theranostic displays excellent stability with no toxicity, and significant uptake in macrophages. Furthermore, it delivers celecoxib to macrophages and reduces PGE2 production from these cells. In vivo studies in a murine paw inflammation model showed nanoemulsion presence at the inflamed site, specifically in COX-2 expressing macrophages compared to neutrophils. Supporting our hypothesis, celecoxib delivered through a nanoemulsion demonstrated time-dependent reduction in fluorescence from the inflamed paw, indicative of reduced macrophage infiltration. In a neuropathic pain model, celecoxib delivered to macrophages led to reduced pain concomitant with reduced macrophage infiltration at the inflamed site compared to free drug control (cross reference: Kiran Vasudeva, Dissertation, 2015). In conclusion, inhibition of COX-2 in macrophages using theranostic nanoemulsions proves to be an effective and generalized strategy facilitating simultaneous therapy and diagnosis, which can be applied to many chronic diseases. The diagnostic information during therapy can be used to tailor the treatment and reduce patient variability leading to personalized medicine

Macrophage COX-2 As a Target For Imaging And Therapy of Inflammatory Diseases Using Theranostic Nanoemulsions

Personalized medicine can be an approach to address the unsatisfactory treatment outcomes in inflammatory conditions such as cancer, arthritis, and cardiovascular diseases. A common feature of chronic diseases is the infiltration of pro-inflammatory macrophages at the disease loci. Infiltrating macrophages have been previously utilized for disease diagnosis. These features suggest that macrophages can be broadly applicable targets for simultaneous therapy and diagnosis. Cyclooxygenase-2 (COX-2), an enzyme involved in the biosynthesis of a lipid inflammatory mediator, prostaglandin E2 (PGE2), is over expressed in macrophages infiltrating the pathological site. Inhibition of PGE2 leads to reduced inflammation, pain and macrophage infiltration. To utilize macrophages for the purpose of simultaneous therapy and diagnosis, we proposed to integrate therapeutic and imaging capabilities on a single nanomedicine platform, referred as theranostics. A stable 19F MRI visible nanoemulsion platform was developed, incorporating celecoxib for COX-2 inhibition and near-infrared fluorescent dye(s) for fluorescence imaging. We hypothesized that inhibition of COX-2 in macrophages using a theranostic nanoemulsion will reduce the inflammation (and pain), and that this response can be visualized by monitoring changes in macrophage infiltration. In vitro characterization demonstrated that the theranostic displays excellent stability with no toxicity, and significant uptake in macrophages. Furthermore, it delivers celecoxib to macrophages and reduces PGE2 production from these cells. In vivo studies in a murine paw inflammation model showed nanoemulsion presence at the inflamed site, specifically in COX-2 expressing macrophages compared to neutrophils. Supporting our hypothesis, celecoxib delivered through a nanoemulsion demonstrated time-dependent reduction in fluorescence from the inflamed paw, indicative of reduced macrophage infiltration. In a neuropathic pain model, celecoxib delivered to macrophages led to reduced pain concomitant with reduced macrophage infiltration at the inflamed site compared to free drug control (cross reference: Kiran Vasudeva, Dissertation, 2015). In conclusion, inhibition of COX-2 in macrophages using theranostic nanoemulsions proves to be an effective and generalized strategy facilitating simultaneous therapy and diagnosis, which can be applied to many chronic diseases. The diagnostic information during therapy can be used to tailor the treatment and reduce patient variability leading to personalized medicine

Actionable Visualization of Higher Dimensional Dynamical Processes

Analyzing modern day\u27s information systems that produce humongous multi-dimensional data in form of logs, traces or events that unfold over time can be tedious without adequate visualization, thereby, advocating the need for an intelligible visualization. This thesis researched and developed a visualization framework that represents multi-dimensional dynamic and temporal process data in a potentially intelligible and actionable form. A prototype showing four different views using notional malware data abstracted from Normal Sandbox behavioral traces were developed. In particular, the B-matrix view representing the DLL files used by the malware to attack a system. This representation is aimed at visualizing large data sets without losing emphasis on the process unfolding over multiple dimensions

Synthesis of 1,2,3-triazole ligands, their metal complexes, and applications in catalysis; Gold (I) catalyzed 1,n-enyne ester cycloisomerization reactions

Dihydronaphthalenes have been prepared from a ligand controlled gold catalyzed enyne cycloisomerization reaction by using water as an additive. Additionally, four membered rings were obtained in the absence of water under similar conditions. This method also provides excellent yields of substituted dihydroquinolines and dihydrobenzopyrans. Both aliphatic and aromatic terminal alkynes provide the cyclic products under the optimized conditions. The reaction represents a novel method for the synthesis of seven-membered rings with moderate yields.;1,2,3-Triazoles have been utilized as ligands in a number of synthetic transformations. In our attempt to mimicking the porphyrin with 1,2,3-triazole by macrocyclization was unsuccessful due to poor solubility. The intermediates, for both analogs were synthesized by using Click chemistry and a Mitsunobu reaction and are characterized by NMR.;In addition to porphyrin analogs, P,N,N pincer-type ligands featuring a 1,2,3-triazole were synthesized, characterized and used to prepare palladium, nickel and gold complexes. These complexes were characterized by homo and hetero nuclear 1D and 2D NMR spectroscopy and X-ray crystallography. Attempts to use the new pincer complexes in organic transformations were unsuccessful. However, several interesting crystal structures including four-coordinate nickel(II) square planar complexes and a k1- benzoate gold(I) complex in which gold is bound to an oxygen atom of a benzoate were obtained