Search results for "Computer Science::Information Retrieval"
showing 10 items of 171 documents
The see-saw portal at future Higgs Factories
2020
We consider an extension of the Standard Model with two right-handed singlet fermions with mass at the electroweak scale that induce neutrino masses, plus a generic new physics sector at a higher scale $\Lambda$. We focus on the effective operators of lowest dimension $d=5$, which induce new production and decay modes for the singlet fermions. We assess the sensitivity of future Higgs Factories, such as FCC-ee, CLIC-380, ILC and CEPC, to the coefficients of these operators for various center of mass energies. We show that future lepton colliders can test the cut-off of the theory up to $\Lambda \simeq 500 - 1000\;$TeV, surpassing the reach of future indirect measurements of the Higgs and $Z…
Non-supersymmetric AdS6 and the swampland
2021
We discuss infinite families of non-supersymmetric AdS$_6$ solutions in Type IIB string theory. They are siblings of supersymmetric solutions which are associated with $(p,q)$ 5-brane webs and holographically dual to 5d SCFTs engineered by those brane webs. The non-supersymmetric backgrounds carry identical 5-brane charges and are connected to the supersymmetric ones by RG flows. We study the stability of the non-supersymmetric solutions, identifying perturbative and non-perturbative decay channels for all the backgrounds explicitly available. We also identify likely decay mechanisms for solutions that have not been constructed explicitly but may be expected to exist based on brane web cons…
Cosmological constraints on heavy sterile neutrinos
2022
We consider heavy sterile neutrinos $\nu_s$, with mass in the range 10 MeV $\lesssim m_s \lesssim m_{\pi} \sim 135$ MeV, thermally produced in the early universe and freezing out after the QCD phase transition. The existence of these neutrinos may alter the value of the effective number of neutrino species $N_{\rm eff}$, measured by the cosmic microwave background (CMB), and the ${}^4$He production during the BBN. We provide a detailed account of the solution of the relevant Boltzmann equations and we identify the parameter space constrained by current Planck satellite data and forecast the parameter space probed by future Stage-4 ground-based CMB (CMB-S4) observations.
A Semantic Layer on Semi-structured Data Sources for Intuitive Chatbots
2009
The main limits of chatbot technology are related to the building of their knowledge representation and to their rigid information retrieval and dialogue capabilities, usually based on simple "pattern matching rules". The analysis of distributional properties of words in a texts corpus allows the creation of semantic spaces where represent and compare natural language elements. This space can be interpreted as a "conceptual" space where the axes represent the latent primitive concepts of the analyzed corpus. The presented work aims at exploiting the properties of a data-driven semantic/conceptual space built using semi-structured data sources freely available on the web, like Wikipedia. Thi…
MHD simulations of the in situ generation of kink and sausage waves in the solar corona by collision of dense plasma clumps
2019
Funding: This research has received funding from the UK Science and Technology Facilities Council (Consolidated Grant ST/K000950/1) and the European Union Horizon 2020 research and innovation programme (grant agreement No. 647214). P.A. acknowledges funding from his STFC Ernest Rutherford Fellowship (No. ST/R004285/1). This research was supported by the Research Council of Norway through its Centres of Excellence scheme, project number 262622. Context. Magnetohydrodynamic (MHD) waves are ubiquitous in the solar corona where the highly structured magnetic fields provide efficient wave guides for their propagation. While MHD waves have been observed originating from lower layers of the solar …
Bounded geometry, growth and topology
2010
We characterize functions which are growth types of Riemannian manifolds of bounded geometry.
Tunnel effect and symmetries for Kramers–Fokker–Planck type operators
2011
AbstractWe study operators of Kramers–Fokker–Planck type in the semiclassical limit, assuming that the exponent of the associated Maxwellian is a Morse function with a finite number n0 of local minima. Under suitable additional assumptions, we show that the first n0 eigenvalues are real and exponentially small, and establish the complete semiclassical asymptotics for these eigenvalues.
Single Particle Jumps in a Binary Lennard-Jones Glass
2002
ABSTRACTWe study a binary Lennard-Jones mixture below the glass transition with molecular dynamics (MD) simulations. To investigate the dynamics of the system we define single particle jumps via their single particle trajectories. We find two kinds of jumps: metastable jumps, where a particle jumps back and forth between two or more states, and real jumps, where a particle does not return to any of its former states. For both the real and metastable jumps we present as a function of temperature the number of jumps, jump size, time between jumps, and energy.
"Table 14" of "Search for magnetic monopoles and stable high-electric-charge objects in 13 TeV proton-proton collisions with the ATLAS detector"
2019
Selection efficiency as a function of transverse kinetic energy $E^\text{kin}_\text{T}=E_\text{kin}\sin\theta$ and pseudorapidity $|\eta|$ for $g=2g_\textrm{D}$ monopoles of mass 500 GeV.
"Table 19" of "Search for magnetic monopoles and stable high-electric-charge objects in 13 TeV proton-proton collisions with the ATLAS detector"
2019
Selection efficiency as a function of transverse kinetic energy $E^\text{kin}_\text{T}=E_\text{kin}\sin\theta$ and pseudorapidity $|\eta|$ for $g=2g_\textrm{D}$ monopoles of mass 3000 GeV.