Greenhouse gas emissions, inventories and validation

The emission of greenhouse gases has become a very high priority research and environmental policy issue due to their effects on global climate. The knowledge of changes in global atmospheric concentrations of greenhouse gases since the industrial revolution is well documented, and the global budgets are reasonably well known. However, even at this scale there are important uncertainties in the budgets, for example, in the case of methane while the main sources and sinks have been identified, temporal changes in the global average concentrations since the early 1990s are not understood. In the absence of a quantitative explanation with appropriate experimental support, it is clear that current knowledge of the causes of changes in the global methane budget is inadequate to predict the effect of changes in specific emission sectors. In developing control strategies to reduce emissions it is necessary to validate national emissions and their spatial disaggregation. The methodology to underpin such a process is at an early stage of development and is not fully implemented in any country, even though target emission reductions have already been announced. Furthermore, the scale of the emission reductions is large (eg of 60% reductions by 2050 relative to 1990 baseline). There is therefore an urgent requirement for measurement based verification processes to support such challenging emission reductions. In this paper we provide the background in greenhouse gas emissions globally and in the UK followed by examples of approaches to validate emissions at the UK scale and within the regions

On sigma-subnormality criteria in finite sigma-soluble groups

[EN] Let sigma = {sigma(i) : i is an element of I} be a partition of the set P of all prime numbers. A subgroup X of a finite group G is called sigma-subnormal in G if there is a chain of subgroups X = X-0 subset of X-1 subset of center dot center dot center dot subset of X-n = G where for every j = 1,..., n the subgroup X j-1 is normal in X j or X j /CoreX j ( X j-1) is a si -group for some i. I. In the special case that s is the partition of P into sets containing exactly one prime each, the sigma-subnormality reduces to the familiar case of subnormality. In this paper some sigma-subnormality criteria for subgroups of s-soluble groups, or groups in which every chief factor is a sigma(i)-group, for some sigma(i) sigma s, are showed.The first and third authors are supported by the grant PGC2018-095140-B-I00 from the Ministerio de Ciencia, Innovacion y Universidades and the Agencia Estatal de Investigacion, Spain, and FEDER, European Union and Prometeo/2017/057 of Generalitat (Valencian Community, Spain). The second author was supported by the State Program of Science Researchers of the Republic of Belarus (Grant 19-54 "Convergence-2020").Ballester-Bolinches, A.; Kamornikov, SF.; Pedraza Aguilera, MC.; Pérez-Calabuig, V. (2020). On sigma-subnormality criteria in finite sigma-soluble groups. Revista de la Real Academia de Ciencias Exactas Físicas y Naturales Serie A Matemáticas. 114(2):1-9. https://doi.org/10.1007/s13398-020-00824-4S191142Amberg, B., Franciosi, S., De Giovanni, F.: Products of Groups. Oxford Mathematical Monographs. Clarendon Press, Oxford (1992)Ballester-Bolinches, A., Ezquerro, L.M.: Classes of Finite Groups, Vol. 584 of Mathematics and its Applications. Springer, New York (2006)Ballester-Bolinches, A., Kamornikov, S.F., Pedraza-Aguilera, M.C., Yi, X.: On -subnormal subgroups of factorised finite groups (Preprint)Casolo, C.: Subnormality in factorizable finite soluble groups. Arch. Math. 57, 12–13 (1991)Doerk, K., Hawkes, T.: Finite Soluble Groups. Walter De Gruyter, Berlin (1992)Fumagalli, Francesco: On subnormality criteria for subgroups in finite groups. J. Lond. Math. Soc. 76(2), 237–252 (2007)Kamornikov, S.F., Shemetkova, O.L.: On $${{\cal{F}}}$$-subnormal subgroups of a finite factorised group. Probl. Phys. Math. Tech. 1, 61–63 (2018)Khukhro, E.I., Mazurov, V.D.: Unsolved Problems in Group Theory. The Kourovka notebook. Institut Matematiki SO RAN, Novosibirsk, No. 19 (2018)Lennox, J.C., Stonehewer, S.E.: Subnormal Subgroups of Groups. Clarendon Press, Oxford (1987)Maier, R.: Um problema da teoria dos subgrupos subnormais. Bol. Soc. Bras. Mat. 8(2), 127–130 (1977)Maier, R., Sidki, R.: A note on subnormality in factorizable finite groups. Arch. Math. 42, 97–101 (1984)Skiba, A.N.: A generalization of a Hall theorem. J. Algebra Appl. 15(4), 13 (2016)Skiba, A.N.: On $$\sigma$$-subnormal and $$\sigma$$-permutable subgroups of finite groups. J. Algebra 436, 1–16 (2015)Skiba, A.N.: On -properties of finite groups I. Probl. Phys. Math. Tech. 4, 89–96 (2014)Skiba, A.N.: On -properties of finite groups II. Probl. Phys. Math. Tech. 3(24), 70–83 (2015)Skiba, A.N.: On some arithmetic properties of finite groups. Note Mat. 36, 65–89 (2016)Wielandt, H.: Subnormalität in faktorisierten endlichen Grupppen. J. Algebra 69, 305–311 (1981

Superembedding methods for 4d N=1 SCFTs

We extend SO(4,2) covariant lightcone embedding methods of four-dimensional CFTs to N=1 superconformal field theory (SCFT). Manifest superconformal SU(2,2|1) invariance is achieved by realizing 4D superconformal space as a surface embedded in the projective superspace spanned by certain complex chiral supermatrices. Because SU(2,2|1) acts linearly on the ambient space, the constraints on correlators implied by superconformal Ward identities are automatically solved in this formalism. Applications include new, compact expressions for correlation functions containing one anti-chiral superfield and arbitrary chiral superfield insertions, and manifestly invariant expressions for the superconformal cross-ratios that parametrize the four-point function of two chiral and two anti-chiral fields. Superconformal expressions for the leading singularities in the OPE of chiral and anti-chiral operators are also given. Because of covariance, our expressions are valid in any superconformally flat background, e.g., AdS_4 or R times S^3.Comment: 33 pages, clarification of constraints, version to appear in PR

Action Learning In Action: How Business Students Strengthen Their Knowledge Bases Through Work-Based Experiential Methods

N/

Overhauser effect in individual InP/GaInP dots

Sizable nuclear spin polarization is pumped in individual InP/GaInP dots in a wide range of external magnetic fields B_ext=0-5T by circularly polarized optical excitation. We observe nuclear polarization of up to ~40% at Bext=1.5T and corresponding to an Overhauser field of ~1.2T. We find a strong feedback of the nuclear spin on the spin pumping efficiency. This feedback, produced by the Overhauser field, leads to nuclear spin bi-stability at low magnetic fields of Bext=0.5-1.5T. We find that the exciton Zeeman energy increases markedly, when the Overhauser field cancels the external field. This counter-intuitive result is shown to arise from the opposite contribution of the electron and hole Zeeman splittings to the total exciton Zeeman energy

Overhauser effect in individual InP/GaInP dots

Sizable nuclear spin polarization is pumped in individual InP/GaInP dots in a wide range of external magnetic fields B_ext=0-5T by circularly polarized optical excitation. We observe nuclear polarization of up to ~40% at Bext=1.5T and corresponding to an Overhauser field of ~1.2T. We find a strong feedback of the nuclear spin on the spin pumping efficiency. This feedback, produced by the Overhauser field, leads to nuclear spin bi-stability at low magnetic fields of Bext=0.5-1.5T. We find that the exciton Zeeman energy increases markedly, when the Overhauser field cancels the external field. This counter-intuitive result is shown to arise from the opposite contribution of the electron and hole Zeeman splittings to the total exciton Zeeman energy

Approaching a strong fourth family

A heavy fourth family is an example of new physics which is well defined and familiar in some respects, but which nevertheless has radical implications. In particular it eliminates a light Higgs description of electroweak symmetry breaking. We discuss an early signal for heavy quarks at the LHC in the form of an excess of "$W$-jets", and as well show how $W$-jets may be useful in the reconstruction of the heavy quark masses. We argue that fourth family quarks can be distinguished from vector-like quarks of a similar mass at roughly the same time that a same sign lepton signal becomes visible. Given the large mass of the fourth neutrino we describe how a picture for neutrino mass emerges in the absence of right-handed neutrinos, and how it suggests the existence of a remnant flavor gauge symmetry. Based on talk given at "Second Workshop on Beyond 3 Generation Standard Model -- New Fermions at the Crossroads of Tevatron and LHC", January 2010, Taipei Taiwan.Comment: 14 pages, 10 figures, references added and slight change