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A logarithm law for nonautonomous systems fastly converging to equilibrium and mean field coupled systems
No full textInternational audienceWe prove that if a nonautonomous system has in a certain sense a fast convergence to equilibrium (faster than any power law behavior) then the time τ_r(x,y) needed for a typical point x to enter for the first time in a ball B(y,r) centered in y, with small radius r scales as the local dimension of the equilibrium measure μ at y, i.e.lim(r→0) log [τ_r(x,y)]/ [-log(r)]We then apply the general result to concrete systems of different kind, showing such a logarithm law for asymptotically authonomous solenoidal maps and mean field coupled expanding maps
Volume growth of Funk geometry and the flags of polytopes
No full text36 pages, 3 figuresInternational audienceWe consider the Holmes-Thompson volume of balls in the Funk geometry on the interior of a convex domain. We conjecture that for a fixed radius, this volume is minimized when the domain is a simplex and the ball is centered at the barycenter, or in the centrally-symmetric case, when the domain is a Hanner polytope. This interpolates between Mahler's conjecture and Kalai's flag conjecture. We verify this conjecture for unconditional domains.For polytopal Funk geometries, we study the asymptotics of the volume of balls of large radius, and compute the two highest-order terms. The highest depends only on the combinatorics, namely on the number of flags. The second highest depends also on the geometry, and thus serves as a geometric analogue of the centro-affine area for polytopes.We then show that for any polytope, the second highest coefficient is minimized by a unique choice of center point, extending the notion of Santaló point. Finally, we show that, in dimension two, this coefficient, with respect to the minimal center point, is uniquely maximized by affine images of the regular polygon
Constraining Glueball Couplings
No full textInternational audienceWe set up a numerical S-matrix bootstrap problem to rigorously constrain bound state couplings given by the residues of poles in elastic amplitudes. We extract upper bounds on these couplings that follow purely from unitarity, crossing symmetry, and the Roy equations within their proven domain of validity. First we consider amplitudes with a single spin 0 or spin 2 bound state, both with or without a self-coupling. Subsequently we investigate amplitudes with the spectrum of bound states corresponding to the estimated glueball masses of pure SU(3) Yang-Mills. In the latter case the 'glue-hedron', the space of allowed couplings, provides a first-principles constraint for future lattice estimates
Search for charged-lepton flavor violation in the production and decay of top quarks using trilepton final states in proton-proton collisions at = 13 TeV
No full textInternational audienceA search is performed for charged-lepton flavor violating processes in top quark (t) production and decay. The data were collected by the CMS experiment from proton-proton collisions at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 138 fb. The selected events are required to contain one opposite-sign electron-muon pair, a third charged lepton (electron or muon), and at least one jet of which no more than one is associated with a bottom quark. Boosted decision trees are used to distinguish signal from background, exploiting differences in the kinematics of the final states particles. The data are consistent with the standard model expectation. Upper limits at 95% confidence level are placed in the context of effective field theory on the Wilson coefficients, which range between 0.024-0.424 TeV depending on the flavor of the associated light quark and the Lorentz structure of the interaction. These limits are converted to upper limits on branching fractions involving up (charm) quarks, teu (tec), of 0.032 (0.498)10, 0.022 (0.369)10, and 0.012 (0.216)10 for tensor-like, vector-like, and scalar-like interactions, respectively
New Paths to Job Creation and Development in Africa: The Promise of Industries Without Smokestacks
Full text linkCountries across Sub-Saharan Africa need to overcome two important challenges to achieve economic development. The first is the creation of large-scale jobs, particularly for its burgeoning number of youth entering the labor market every year. The second is a sustained increase in produc-tivity to raise standards of living and break the poverty cycle for millions of people. In other parts of the world, both these challenges have been histori-cally achieved through the development of the industrial sector. The rela-tively high labor intensity of industry has made it a viable destination for labor moving out of agriculture at the start of the economic development journey. Also, because productivity tends to be higher in industry than in agriculture, the movement of labor from agriculture to industry has raised the economy-wide productivity and accelerated structural transformation.
However, the traditional industrial sector has been less dynamic in Africa, certainly in comparison with fast-growing East Asia. Industrial activity and employment in African countries have tended to peak at lower shares of gross domestic product in earlier stages of economic development—a phe-nomenon known as premature deindustrialization. Even though manufac-turing was expanding in Africa, other sectors have been expanding much more quickly. In part, this reflects technological progress in communication, expansion of the internet, and new forms of business organization including global value chains. Given these trends, how can Africa create productive jobs for its large and growing youth population and achieve structural trans-formation if the well-trodden path of industrial development has become difficult to replicate
The Domestics Savings Shortfall in Sub-Saharan Africa : What Can Be Done About It?
Full text linkDomestic financing plays a crucial role in the revenue collection efforts of devel-oping countries. Countries with high domestic savings rates tend to experience higher economic growth rates than others. The greater the domestic savings, the greater is the much-needed flexibility to implement homegrown policies to confront growth and development challenges. Furthermore, a high savings rate reduces vulnerability to sudden shifts in international capital flows.
However, efforts to increase domestic savings rates have not met with much suc-cess in low-income countries, especially in Sub-Saharan Africa, despite financial liberalization and sound macroeconomic policies. We need to know more about the ways to increase domestic financing in these countries.
To address the knowledge gap, the United Nations University World Institute for Development Economics Research (UNU-WIDER) has conducted the project ‘The Domestic Savings Shortfall in Developing Countries—What Can Be Done about It?’ in collaboration with the Kenya Institute for Public Policy Research and Analysis (KIPPRA). Four years of research efforts are now distilled within this book. I sincerely thank the chapter authors for their scholarly contributions and my fellow editor, Rose Ngugi, for her editorial skills in bringing this rich research to publication.
This research project was undertaken with special financial support from the Norwegian Agency for Development Cooperation (Norad), for which all par-ties are most grateful. UNU-WIDER gratefully acknowledges the support and financial contribution to its work programme by the institute’s core donors of the governments of Finland and Sweden. Without this vital funding, our research and policy advisory work would be impossible
Tharaka Nithi County Regenerative Agriculture Food System Transformation Strategy 2025-2030
Full text linkAgriculture is a cornerstone of Kenya's economic and social development, contributing approximately 25% to GDP and 60% of export earnings. As the primary source of livelihood for 80% of the rural population, agriculture holds immense potential to alleviate poverty and hunger, aligning with Sustainable Development Goals 1 and 2. The Constitution of Kenya mandates county governments with the responsibility of formulating regenerative agricultural policies and implementing key regenerative agricultural components. This includes crop and animal husbandry, fisheries development, and plant and animal disease control. Recognizing the fundamental right of every individual to be free from hunger, the county government aims to develop strategies that ensure food and nutrition security. Cognisant of this, through this policy the county government seeks to develop a robust regenerative agricultural development agenda aligned with the Constitution of Kenya and Vision 2030.Addressing current challenges in the agricultural sector through best practices and sustainable resource management. Mitigating the impacts of climate change and building resilience in the food and nutrition security strategies. Strengthening institutional linkages and capacity within the agricultural sector. Addressing cross-cutting issues such as climate change, youth and gender, and diminishing resources. Prioritising food, health, and security as interconnected elements of personal, household, county, and national well-being and allocating adequate resources for sustainable production and value addition in the agricultural sector. By implementing this regenerative agricultural strategy, Tharaka Nithi County aims to achieve a more prosperous and resilient future. The county government calls upon all residents to unite and participate in its implementation. Through collaboration with the national government, private sector, and development partners, the county will strive to improve the livelihoods and well-being of its people
Machakos County Succession Management Policy for the Public Service
Full text linkThe Succession Management Policy is designed to ensure continuity in service delivery by preparing for leadership and workforce transitions within the Machakos County Public Service. It provides a structured approach to identifying and developing employees for key positions to minimize disruptions caused by retirements, resignations, or unexpected vacancies.
The policy emphasizes talent development through mentorship, training, and career progression programs, ensuring that critical skills and institutional knowledge are retained within the county. It also outlines succession planning strategies for different roles, focusing on competency-based promotion and workforce sustainability. By implementing this policy, the county aims to build a resilient, future-ready workforce capable of sustaining long-term development goals
Guidelines for Promotion, Development and Management of Irrigation in Kenya
Full text linkKenya has an area of approximately 582,646 square kilometres, out of this only 17% falls within medium to high rainfall areas, which are suitable for rain-fed agriculture. The rest is arid and semi-arid lands (ASALs), which have highly variable, erratic and unreliable rainfall for sustainable agricultural production. Generally, rain-fed agricultural production is constrained by impacts of climate change and variability. Hence the need to shift focus from rain-fed to irrigated agriculture. The opportunities for economic growth through irrigation are immense, particularly in realizing food security and job creation. Irrigation is recognized as a key enabler for the transformation and growth of agriculture as envisaged under the Kenya Vision 2030 and the Big Four Agenda to achieve 100% food and nutrition security.
The Constitution of Kenya 2010 provides for the citizens the right to be free from hunger and to have adequate food of acceptable quality. It establishes distinct and interdependent National and county governments with specific, residual, concurrent functions and powers as prescribed under Article 186 and the Fourth Schedule. The two levels of government are to operate through cooperation and consultation. The Irrigation Act, 2019, empowers the Cabinet Secretary responsible for irrigation to develop general principles, guidelines and standards for promoting development, coordination and planning of irrigation. It is in this context that the Ministry has developed these Guidelines for promotion, development and management of irrigation in Kenya, hereby referred to as ‘Guidelines’
