Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
896
result(s) for
"Radu, E"
Sort by:
Einstein-Maxwell-scalar black holes: classes of solutions, dyons and extremality
by
Astefanesei, D.
,
Herdeiro, C.
,
Pombo, A.
in
Black Holes
,
Classical and Quantum Gravitation
,
Classical Theories of Gravity
2019
A
bstract
Spherical black hole (BH) solutions in Einstein-Maxwell-scalar (EMS) models wherein the scalar field is non-minimally coupled to the Maxwell invariant by some coupling function are discussed. We suggest a classification for these models into two classes, based on the properties of the coupling function, which, in particular, allow, or not, the Reissner- Nordström (RN) BH solution of electrovacuum to solve a given model. Then, a comparative analysis of two illustrative families of solutions, one belonging to each class is performed:
dilatonic
versus
scalarised
BHs. By including magnetic charge, that is considering dyons, we show that scalarised BHs can have a smooth extremal limit, unlike purely electric or magnetic solutions. In particular, we study this extremal limit using the entropy function formalism, which provides insight on why both charges are necessary for extremal solutions to exist.
Journal Article
Gregory-Laflamme-type instability of boson strings and related phases in D = 5 Kaluza-Klein theory
by
Herdeiro, C.
,
Radu, E.
in
Black holes
,
Classical and Quantum Gravitation
,
Classical Theories of Gravity
2025
A
bstract
We add an
S
1
extra dimension (size
L
) to the well known
D
= 4 static, spherically symmetric
Q
-balls and boson stars. We show that the resulting
uniform horizonless boson strings
possess a static zero-mode for a critical value of
L
. This is at the threshold of a Gregory-Laflamme instability of these objects, occurring for larger values of
L
. The non-linear continuation of the zero-mode yields
D
= 5
non-uniform boson strings
. In addition, there are also intrinsic
D
= 5 solutions describing
localized boson stars on the S
1
, supported by the contribution of the scalar field Kaluza-Klein modes. Basic properties of all three types of aforementioned solutions are discussed, together with their phase space.
Journal Article
Einstein–Dirac–Maxwell wormholes: ansatz, construction and properties of symmetric solutions
2022
We present a discussion of the traversable wormholes in Einstein–Dirac–Maxwell theory recently reported in e-Print: 2010.07317. This includes a detailed description of the ansatz and junction condition, together with an investigation of the domain of existence of the solutions. In this study, we assume symmetry under interchange of the two asymptotically flat regions of a wormhole. Possible issues and limitations of the approach are also discussed.
Journal Article
Introduction pages, NBHA-CN 54(1), 2026
2026
The papers published in Notulae Botanicae Horti Agrobotanici Cluj-Napoca, Issue 1, Volume 54, 2026, represent exciting new research in different topics of life science, specifically in plant science, horticulture, agronomy, crop science, and forestry. Among the interesting articles, we invite you to find news about: A comprehensive framework for introducing novel crops into new agroecological regions; Seaweed-derived biostimulants and plant salinity stress: chemical diversity, mechanisms, and biochemical constraints; Genetic diversity assessment of Lotus corniculatus L. using SCoT and DAMD molecular markers; Melatonin mediated modulation of physiological, biochemical and gene expression patterns governing salinity tolerance in Capsicum frutescens; Identification of submergence-tolerant rice genotypes: a comprehensive analysis of survival and growth parameters in germination stage; Unveiling the potential of silicon as seed priming agent to improve the tolerance in alfalfa against salinity stress; Arbuscular mycorrhizal fungi diversity associated with Capsicum annuum var. glabriusculum in tropical soils; Alternative medium for the isolation, identification, and cultivation of fungi; Nano-SiO2 seed priming improves salinity tolerance in chili (Capsicum frutescens L.) by maintaining ion homeostasis and antioxidant redox balance; Antioxidant and anti-inflammatory activity of Pinus mugo needle extract in experimental acute inflammation; Environmental factors associated with variation in airborne pollen concentrations revealed by automated aerobiological measurements; Effects of glycine betaine application on growth and quality of four cool-season turfgrass species under salinity stress.
Journal Article
Introduction pages, NBHA-CN 53(2), 2025
2025
The papers published in Notulae Botanicae Horti Agrobotanici Cluj-Napoca, Issue 2, Volume 53, 2025, represent new exciting research in different topics of life science, respectively in plant science, horticulture, agronomy, crop science, and forestry. Among the interesting articles, we invite you to find news about: Amplicon sequencing reveals different microbial communities between growing and non-growing seasons in the soils of Pinus armandi forestland in Shennongjia, China; Enhancing phytochemical content and bioactive aspects in somatic embryogenesis developed from callus of Phoenix dactylifera L.; Assessment of genetic architecture of cotton germplasm for drought tolerance: A focus on morpho-physiological and biochemical attributes; Diversity and effectiveness of arbuscular mycorrhizal fungi species in alleviating drought stress in tomato; Site-specific factors influencing Hymenoscyphus fraxineus spore dispersal: the role of understorey vegetation and slope steepness in ash dieback spread; Genetic characterization of Greek chestnut (Castanea sativa Mill.) germplasm collections in Parnon mountain; Syringa josikaea (Oleaceae) biotopes in the Ukrainian Carpathians: Climatic conditions and current dynamics; Propagation and community perspective of the climber species Smilax nageliana A.DC. endemic to Java Island; Improvement of quality, physiological parameters and antioxidant status of chrysanthemum by priming of seedlings with UV-A radiation; Silicon dioxide nanoparticles a strategy to improve the growth, physiology, yield, and nutraceutical quality of tomatoes.
Journal Article
Introduction pages, NBHA-CN 53(4), 2025
2025
The papers published in Notulae Botanicae Horti Agrobotanici Cluj-Napoca, Issue 4, Volume 53, 2025, represent exciting new research in different topics of life science, specifically in plant science, horticulture, agronomy, crop science, and forestry. Among the interesting articles, we invite you to find news about: Ethnomedicinal, ecological, phytochemical, nutritional and pharmacological aspects of Sanguisorba officinalis L. (Rosaceae): A comprehensive review; Impact of varying water stress periods (water shortage vs. waterlogging) on Cannabis sativa growth, leaf physiology, and CBD content; Abiotic stress in quinoa: A comprehensive review on the impact of salinity and mitigation strategies; Artificial intelligence for climate-smart agriculture: Enhancing food security and plant adaptation; Selenium nanoparticles mitigate lead-induced genotoxicity and phytotoxicity in Pisum sativum by modulating LOX1 and JAR1 gene expression; Characterization and functional insights of photosynthetic genes MnPsbA, MnRbcL, and MnRCA in mulberry; Pan-genome wide identification and expression analysis of the OFP family genes in response to abiotic and biotic stresses in cucumber; Phytochemical profiling and SCOT marker analysis reveal genetic diversity in Ziziphus mauritiana genotypes; Mitigating cadmium (Cd) toxicity and enhancing growth, yield, and antioxidant defence of wheat (Triticum aestivum L.) through silicon fertilizers; Preharvest application of biostimulants to improve growth, quality, and yield of blueberry (Vaccinium corymbosum L.); Impact of altitude on the performance and anthocyanin concentration in five varieties of purple corn in the Peruvian Amazon.
Journal Article
Introduction pages, NBHA-CN 53(1), 2025
2025
The papers published in Notulae Botanicae Horti Agrobotanici Cluj-Napoca, Issue 1, Volume 53, 2025, represent new exciting research in different topics of life science, respectively in plant science, horticulture, agronomy, crop science, and forestry. Among the interesting articles, we invite you to find news about: Resilience of forests in a changing climate: Responses, mechanisms, and adaptations; A panoramic review on phytochemistry, pharmacological potential, health benefits, and versatility of Solanum tuberosum L.; Role of molecular breeding in understanding salinity tolerance in cotton: limitations and perspectives; Evaluation of gas chromatography-mass spectrometry analysis and yield attributing traits of caffeine treated Trigonella corniculata L.; Induction and expression of systemic resistance to downy mildew disease in grapevine by chitosan; Molecular insights of pigeonpea sterility mosaic virus mixed infections and its variability in pigeonpea; Assessing the impact of different water stresses on physio-chemical properties and yield-related traits in tomato genotypes: Insights into stability and response; Biochemical and Raman spectroscopic insights into plant-mold interactions; Assessing genetic diversity and population structure in Tulipa species from Türkiye and Kazakhstan; Elicitation effect of hydrogen peroxide to enhance tolerance of Taxodium distichum (L.) Rich. seedlings irrigated with saline water; Effects of different rootstocks on the growth physiology and enzyme activity of Artemisia selengensis; Comparative analysis of bioactive compounds identified in the fruits of three chokeberry (Aronia melanocarpa) cultivars in different cultivation systems; The impact of cultivar and production conditions on apple quality; Biochemical attributes Portulaca oleracea as affected by manganese oxide and magnesium oxide nanoparticles; Identification of arbuscular mycorrhizal fungi in queñua (Polylepis rugulosa) in the forest of southern Peru.
Journal Article
Introduction pages, NBHA-CN 53(3), 2025
2025
The papers published in Notulae Botanicae Horti Agrobotanici Cluj-Napoca, Issue 3, Volume 53, 2025, represent new exciting research in different topics of life science, respectively in plant science, horticulture, agronomy, crop science, and forestry. Among the interesting articles, we invite you to find news about: Livestock-mediated food waste conversion: Advancing resource efficiency and sustainable agriculture; The genetic applications of plant cell and tissue culture techniques: Essential tools for genetic manipulation and crop improvement; Transcriptome analysis of wheat (Triticum aestivum) reveals regulatory mechanisms of adaptation to water deficit stress induced by arbuscular mycorrhizal fungi; Potential role of nitrogen supplementation in alleviating flooding stress; Ameliorative role of salicylic acid on morpho-anatomy and physiology of rapeseed (Brassica napus L.) under lead stress; Enhanced accumulation of total phenolic content and rosmarinic acid in cell suspension cultures of Ehretia asperula using elicitors and precursors; Influence of cultivation conditions on growth and water use efficiency of zucchini seedlings; Synergistic effects of humic acid and boron on quantitative and qualitative traits of tomato; Determination of yield by plant leaf temperature and thermal imaging in banana (Musa spp. AAA) under different cover materials; Biomass, carbon sequestration, and physiological behaviours of Paulownia ‘Shan Tong’ plantation under a semi-arid bioclimate; Variation in survival and stem quality of Douglas-fir provenances: Insights from 47-year-old common garden experiments in Romania.
Journal Article
Kaluza-Klein monopole with scalar hair
2024
A
bstract
We construct a new family of rotating black holes with scalar hair and a regular horizon of spherical topology, within five dimensional (
d
= 5) Einstein’s gravity minimally coupled to a complex, massive scalar field doublet. These solutions represent generalizations of the Kaluza-Klein monopole found by Gross, Perry and Sorkin, with a twisted
S
1
bundle over a four dimensional Minkowski spacetime being approached in the far field. The black holes are described by their mass, angular momentum, tension and a conserved Noether charge measuring the hairiness of the configurations. They are supported by rotation and have no static limit, while for vanishing horizon size, they reduce to boson stars. When performing a Kaluza-Klein reduction, the
d
= 5 solutions yield a family of
d
= 4 spherically symmetric dyonic black holes with gauged scalar hair. This provides a link between two seemingly unrelated mechanisms to endow a black hole with scalar hair: the
d
= 5
synchronization condition
between the scalar field frequency and the event horizon angular velocity results in the
d
= 4
resonance condition
between the scalar field frequency and the electrostatic chemical potential.
Journal Article
Introduction pages, NBHA-CN 52(2), 2024
2024
The papers published in Notulae Botanicae Horti Agrobotanici Cluj-Napoca, Issue 2, Volume 52, 2024 represent new exciting research in different topics of life science, respectively in plant science, horticulture, agronomy, crop science, and forestry. Among the interesting articles, we invite you to find news about: Enhancing plant resistance to biotic stresses through rhizobacteria for sustainable agriculture; Efficacy of different bioagents in suppressing Meloidogyne incognita, and evaluation of some physio-biochemical changes in Phaseolus vulgaris L.; Diagnostic study of nitrogen nutrition in cotton based on unmanned aerial vehicle RGB images; Changes in growth, antioxidant, anti-Alzheimer, and antidiabetic potential of lamb’s lettuce Valerianella locusta grown hydroponically and on soil in response to salinity; Titanium dioxide nanoparticles (TiO2-NPs) effect on germination and morphological parameters in alfalfa, tomato, and pepper; Synthesize of bio-based encapsulated nano urea modified hydroxyapatite for controlling release of nitrogen and enhancing green bean yield; Comparison of pepper accessions acting as rootstocks: A case with low P inputs; Marine actinomycetes for biocontrol of Fusarium solani in tomato plants: In vitro and in vivo studies; How the application of supporting substances affects the formation of fertile embryos of crossbred cherries and its germination.
Journal Article