Is India on the right pathway to reduce CO2 emissions? Decomposing an enlarged Kaya identity using the LMDI method for the period 1990-2016.

Nowadays, India is the third-largest CO2 emitter and energy consumer in the world, and, it is soon expected to surpass China as the most populated country. Therefore, it is of great interest to analyse how India is developing its energy transition to a lower-carbon economy. This work analyses the evolution of the main driving forces of CO2 emissions in India during the period 1990-2016 through the use of an enlarged version of the Kaya identity, which establishes a link between CO2 emissions, types of energy sources (16), size of the economic sectors (3) and value of the Gross Domestic Product. India's CO2 emissions increased by 276% in the period under study, due to the rapid economic growth of India, which has been the dominating driving force contributing to the increase in CO2 emissions by 241%, while the energy intensity has been the main one reducing them by approximately -47%. So far, the use of coal has supported the rapid economic growth and the contribution of renewable energy, although significant, is still short compared to the total amount of energy employed. Remarkably, the estimated value of the emission intensity for 2020 supposes a 26% reduction concerning the value in 2005. According to this result, India is on the right pathway to fulfil its Nationally Determined Contribution but not to reduce its net CO2 emissions.

Shape coexistence in the neutron-deficient even-even (182-188)Hg isotopes studied via coulomb excitation.

Coulomb-excitation experiments to study electromagnetic properties of radioactive even-even Hg isotopes were performed with 2.85 MeV/nucleon mercury beams from REX-ISOLDE. Magnitudes and relative signs of the reduced E2 matrix elements that couple the ground state and low-lying excited states in Hg182-188 were extracted. Information on the deformation of the ground and the first excited 0+ states was deduced using the quadrupole sum rules approach. Results show that the ground state is slightly deformed and of oblate nature, while a larger deformation for the excited 0+ state was noted in Hg182,184. The results are compared to beyond mean field and interacting-boson based models and interpreted within a two-state mixing model. Partial agreement with the model calculations was obtained. The presence of two different structures in the light even-mass mercury isotopes that coexist at low excitation energy is firmly established.

Excited-state phase transition and onset of chaos in quantum optical models.

We study the critical behavior of excited states and its relation to order and chaos in the Jaynes-Cummings and Dicke models of quantum optics. We show that both models exhibit a chain of excited-state quantum phase transitions demarcating the upper edge of the superradiant phase. For the Dicke model, the signatures of criticality in excited states are blurred by the onset of quantum chaos. We show that the emergence of quantum chaos is caused by the precursors of the excited-state quantum phase transition.

Partial dynamical symmetry in quantum Hamiltonians with higher-order terms.

A generic procedure is proposed to construct many-body quantum Hamiltonians with partial dynamical symmetry. It is based on a tensor decomposition of the Hamiltonian and allows the construction of a hierarchy of interactions that have selected classes of solvable states. The method is illustrated in the SO(6) limit of the interacting boson model of atomic nuclei and applied to the nucleus 196Pt.

Observation of two-proton radioactivity of 19Mg by tracking the decay products.

We have observed the two-proton radioactivity of the previously unknown (19)Mg ground state by tracking the decay products in-flight. For the first time, the trajectories of the 2p-decay products, (17)Ne+p+p, have been measured by using tracking microstrip detectors which allowed us to reconstruct the 2p-decay vertices and fragment correlations. The half-life of (19)Mg deduced from the measured vertex distribution is 4.0(15) ps in the system of (19)Mg. The Q value of the 2p decay of the (19)Mg ground state inferred from the measured p-p-(17)Ne correlations is 0.75(5) MeV.

Phase diagram of the proton-neutron interacting boson model.

We study the phase diagram of the proton-neutron interacting boson model with special emphasis on the phase transitions leading to triaxial phases. The existence of a new critical point between spherical and triaxial shapes is reported.

Quantum phase transitions in the interacting boson model: integrability, level repulsion, and level crossing.

We study the quantum phase transition mechanisms that arise in the interacting boson model. We show that the second-order nature of the phase transition from U(5) to O(6) may be attributed to quantum integrability, whereas all the first-order phase transitions of the model are due to level repulsion with one singular point of level crossing. We propose a model Hamiltonian with a true first-order phase transition for finite systems due to level crossings.