We show that, as a consequence of the local Poincaré symmetry, gravity and matter fields have to be entangled, unless the overall action is carefully fine-tuned. First, we present a general argument, ...applicable to any particular theory of quantum gravity with matter, by performing the analysis in the abstract nonperturbative canonical framework, demonstrating the nonseparability of the scalar constraint, thus promoting the entangled states as the physical ones. Also, within the covariant framework, using a particular toy model, we show explicitly that the Hartle-Hawking state in the Regge model of quantum gravity is entangled. Our result is potentially relevant for the quantum-to-classical transition, taken within the framework of the decoherence programme: due to the gauge symmetry requirements, the matter does not decohere, it is by default decohered by gravity. Generically, entanglement is a consequence of interaction. This new entanglement could potentially, in form of an 'effective interaction', bring about corrections to the weak equivalence principle, further confirming that spacetime as a smooth four-dimensional manifold is an emergent phenomenon. Finally, the existence of the gauge-protected entanglement between gravity and matter could be seen as a criterion for a plausible theory of quantum gravity, and in the case of perturbative quantisation approaches, a confirmation of the persistence of the manifestly broken gauge symmetry.
We perform the complete Hamiltonian analysis of the BFCG action for general relativity. We determine all the constraints of the theory and classify them into the first-class and the second-class ...constraints. We also show how the canonical formulation of BFCG general relativity reduces to the Einstein-Cartan and triad canonical formulations. The reduced phase space analysis also gives a 2-connection which is suitable for the construction of a spin-foam basis which will be a categorical generalization of the spin-network basis from loop quantum gravity.
We show that general relativity can be formulated as a constrained topological theory for flat 2-connections associated with the Poincaré 2-group. Matter can be consistently coupled to gravity in ...this formulation. We also show that the edge lengths of the spacetime manifold triangulation arise as the basic variables in the path-integral quantization, while the state-sum amplitude is an evaluation of a colored 3-complex, in agreement with the category theory results. A 3-complex amplitude for Euclidean quantum gravity is proposed.
We perform the full Hamiltonian analysis of the topological BFCG action based on the Poincaré 2-group. The Hamiltonian of the theory is constructed, and the algebra of constraints is computed. The ...Dirac brackets are evaluated, and the second class constraints are then eliminated from the theory. The results are contrasted with those of the topological Poincaré gauge theory, which is equivalent to the BFCG model at the level of the classical action, but has a very different Hamiltonian structure.
The upgrade of the CMS experiment for the high luminosity operation of the LHC comprises the replacement of the current endcap calorimeter by a high granularity sampling calorimeter (HGCAL). The ...electromagnetic section of the HGCAL is based on silicon sensors interspersed between lead and copper (or copper tungsten) absorbers. The hadronic section uses layers of stainless steel as an absorbing medium and silicon sensors as an active medium in the regions of high radiation exposure, and scintillator tiles directly readout by silicon photomultipliers in the remaining regions. As part of the development of the detector and its readout electronic components, a section of a silicon-based HGCAL prototype detector along with a section of the CALICE AHCAL prototype was exposed to muons, electrons and charged pions in beam test experiments at the H2 beamline at the CERN SPS in October 2018. The AHCAL uses the same technology as foreseen for the HGCAL but with much finer longitudinal segmentation. The performance of the calorimeters in terms of energy response and resolution, longitudinal and transverse shower profiles is studied using negatively charged pions, and is compared to GEANT4 predictions. This is the first report summarizing results of hadronic showers measured by the HGCAL prototype using beam test data.
There is a complex interplay between the structural and other physicochemical properties of new compounds and the molecules in living organisms. To understand the mechanism of the interactions at the ...molecular level, the correlations between the selected properties and their biological responses have to be examined. With this aim, in this paper, density functional theory (DFT) and LMP2 calculations were carried out for the 2-acetylpyridine-aminoguanidine ligand,
L
, and its copper(
ii
) complexes containing different monoanionic ligands. In addition, several parameters, most frequently used for the prediction of drug-likeness of new compounds, were calculated. The influence of the compounds on the effectiveness of the reference chemotherapeutic drug cisplatin was determined
in vitro
, by comparison of their combination indices (CIs). The drug interactions between cisplatin and the earlier synthesized ligands
L1
(bis(3-chloropyridazine-6-hydrazone)-2,6-diacetylpyridine) and
L2
(bis(phthalazine-1-hydrazone)-2,6-diacetylpyridine) and their Co(
iii
), Ni(
ii
), Cu(
ii
) and Zn(
ii
) complexes, respectively, were also measured. The ligands
L
,
L2
, and
L3
, as well as their complexes, showed different interactions in combination with cisplatin from strong antagonism of
L
to strong synergism of
4-L1
and
4-L2
. The experimental results and the calculated parameters were analyzed to evaluate their correlation with the measured interactions. The thermal stability of the
L·2HCl
ligand and its four copper(
ii
) complexes was determined and the thermal stability data were correlated to selected calculated molecular descriptors.
There is a complex interplay between the structural and other physicochemical properties of new compounds and the molecules in living organisms.
The asymmetric unit of the title compound, (C12H18N3O4)2ZnCl4·CH3OH, consists of two Girard reagent-based cations, a tetrachloridozincate anion and a molecule of methanol as solvate. These ...components are interconnected in the crystal structure by an extensive network of O—H...O, N—H...O, C—H...O, O—H...N, O—H...Cl, N—H...Cl and C—H...Cl hydrogen bonds. The shortest intermolecular interaction is realized between the cation and anion H...Cl = 2.29 (5) Å; O—H...Cl = 167 (3)°. C—H...O interactions also play a important role in the interconnection of the cations.
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