ESAR: Energy Saving Ad Hoc Routing Protocol for Mobile Ad Hoc Networks

Mobile ad hoc networks support multi hop routing where the deployment of central base station is neither economic nor easy. Efficient routing of the packets is a major challenge in the ad hoc networks. There exist several proactive (like DSDV etc.) and reactive (Like AODV etc.) routing algorithms for the dynamic networks.The ESAR algorithm selects the path with minimum cost value indicating that the path has the shortest distance to the destination and has the maximum of the minimum available battery power of the node among the different paths. This selected path is chosen as the best path for packet transmission till any node in the path exhausts battery power beyond a threshold value. At this point of time, a backup path having the next lower cost is selected as an alternate path for packet transmission. The process is repeated till all the paths from the same source to destination are exhausted with their battery power. When this situation occurs, the cost of the paths is re-calculated and the process continues. The simulation result of the proposed algorithm ESAR enhances the network life time over the AODV and EEAODR algorithm

Theoretical Priors and the Dark Energy Equation of State

We revisit the theoretical priors used for inferring Dark Energy (DE) parameters. Any DE model must have some form of a tracker mechanism such that it behaved as matter or radiation in the past. Otherwise, the model is fine-tuned. We construct a model-independent parametrization that takes this prior into account and allows for a relatively sudden transition between radiation/matter to DE behavior. We match the parametrization with current data, and deduce that the adiabatic and effective sound speeds of DE play an important role in inferring the cosmological parameters. We find that there is a preferred transition redshift of $1+z\simeq 29-30$, and some reduction in the Hubble and Large Scale Structure tensions.Comment: 51 Pages, 11 figures, 19 Tables including appendices, Comments are welcome, references and footnote adde

Blackhole in Nonlocal Gravity: Comparing Metric from Newmann-Janis Algorithm with Slowly Rotating Solution

The strong gravitational field near massive blackhole is an interesting regime to test General Relativity(GR) and modified gravity theories. The knowledge of spacetime metric around a blackhole is a primary step for such tests. Solving field equations for rotating blackhole is extremely challenging task for the most modified gravity theories. Though the derivation of Kerr metric of GR is also demanding job, the magical Newmann-Janis algorithm does it without actually solving Einstein equation for rotating blackhole. Due to this notable success of Newmann-Janis algorithm in the case of Kerr metric, it has been being used to obtain rotating blackhole solution in modified gravity theories. In this work, we derive the spacetime metric for the external region of a rotating blackhole in a nonlocal gravity theory using Newmann-Janis algorithm. We also derive metric for a slowly rotating blackhole by perturbatively solving field equations of the theory. We discuss the applicability of Newmann-Janis algorithm to nonlocal gravity by comparing slow rotation limit of the metric obtained through Newmann-Janis algorithm with slowly rotating solution of the field equation.Comment: 8 pages, 1 figure, minor corrections, references added; to appear in EPJ

Essays in Development Economics with a Focus on Gender, Health, and the Environment

This thesis comprises three chapters on topics in development economics. The first chapter studies access to maternal healthcare in markets with vertically differentiated public and private providers. The second chapter studies the efficacy of induction stoves in reducing indoor air pollution in rural households when faced with erratic power supply. Finally, the third chapter studies the role of financial incentives in correcting disparities in sex ratios. All three chapters study the context of India but are representative of important development issues in low-income countries. The first chapter titled "Equilibrium Effects of Subsidizing Public Services" studies one of India's largest welfare schemes Janani Suraksha Yojana (JSY) that incentivized pregnant women in India to access institutional maternal care at public hospitals. We argue that governments can make complementary investments to improve welfare gains from large scale policies. JSY did not improve health outcomes despite a substantial increase in the take-up of institutional care. We document three equilibrium responses that explain this policy failure. First, JSY led to a mismatch of risk across health facilities -- high-risk mothers sorted out of highest quality care at private facilities. Second, in line with the literature, public sector quality deteriorated as a result of congestion. This resulted in lower quality care for both marginal as well as infra-marginal patients at public hospitals. We show that only mothers with high socio-economic status adapted to the worsening quality of care at public hospitals by sorting into more expensive private hospitals. Third, despite increased competition, private hospitals maintained high prices, crowding out riskier and poorer mothers. We do not find evidence that private hospitals improved healthcare quality to justify higher prices. The second chapter titled "Electric Stoves as a Solution for Household Air Pollution" is an interdisciplinary field-based research study that studies the role of reliable electricity in inducing rural Indian households to switch away from dirty cooking fuels towards a clean cooking technology, induction cookstoves, thereby reducing the exposure to high levels of indoor air pollution. We collected minute-by-minute data on electricity availability, electric induction stove use, and kitchen and outdoor particulate pollution in a sample of rural Indian households for one year. Using within household-month variation generated by unpredictable outages, we estimate the effects of electricity availability and electric induction stove use on kitchen PM2.5 concentration at each hour of the day. Electricity availability reduces kitchen PM2.5 by up to 50 ??/?3, which is between 10 and 20 percent of peak concentrations during cooking hours. Induction stove use instrumented by electricity availability reduces PM2.5 in kitchens by 200-450 ??/?3 during cooking hours. The final chapter titled "Can Large-Scale Conditional Cash Transfers Resolve the Fertility-Sex Ratio Trade-off? Evidence from India" studies a large-scale conditional cash transfer (CCT) scheme Ladli Laxmi Yojana that offered cash incentives to households upon the birth of girl children. The policy also offered substantial incentive for investing in girls' education. In my evaluation of the Ladli Laxmi Yojana in Madhya Pradesh, India. I find that financial incentives aimed at the girl child increased average fertility by about 0.15 children per household (on baseline average of 0.93 children) children per household and improved sex-ratio by 3%. This points to the well known fertility-sex ratio trade-off. Moreover, these effects are quite opposite to a similar CCT scheme in Haryana (Anukriti, 2018) suggesting context dependence of such policies