Canonical Energy Research Articles

Testing H0 in acoustic dark energy models with Planck and ACT polarization data

The canonical acoustic dark energy model (cADE), which is based on a scalar field with a canonical kinetic term that rapidly converts potential to kinetic energy around matter radiation equality, alleviates the Hubble tension found in $\Lambda$CDM. We show that it successfully passes new consistency tests in the CMB damping tail provided by the ACT data, while being increasingly constrained and distinguished from alternate mechanisms by the improved CMB acoustic polarization data from Planck. The best fit cADE model to a suite of cosmological observations, including the SH0ES $H_0$ measurement, has $H_0=70.25$ compared with $68.23$ (km s$^{-1}$ Mpc$^{-1}$) in $\Lambda$CDM and a finite cADE component is preferred at the $2.8\sigma$ level. The ability to raise $H_0$ is now mainly constrained by the improved Planck acoustic polarization data, which also plays a crucial role in distinguishing cADE from the wider class of early dark energy models. ACT and Planck TE polarization data are currently mildly discrepant in normalization and drive correspondingly different preferences in parameters. Improved constraints on intermediate scale polarization approaching the cosmic variance limit will be an incisive test of the acoustic dynamics of these models and their alternatives.

Stability in the higher derivative Abelian gauge field theories

We present an exact derivation of conserved tensors associated to the higher-order symmetries in the higher derivative Abelian gauge field theories. In our model, the wave operator of the derived theory is a n-th order polynomial expressed in terms of the usual Maxwell operator. Relying on this formalism and utilizing the extension of Noether's theorem, we acquire a series of conserved second-rank tensors which includes the standard canonical energy-momentum tensors. Moreover, with the aid of auxiliary fields, we succeed in obtaining the relations between the root decomposition of characteristic polynomial of the wave operator and the conserved energy-momentum tensors in the context of another equivalent lower-order representation. Under the certain conditions, although the canonical energy of the higher derivative dynamics is unbounded from below, the 00-component of the linear combination of these conserved quantities is bounded. By this reason, the original derived theory is considered stable. Finally, as an instructive example, we elaborate the third-order derived system and analyze the stabilities in different cases of root decomposition of the characteristic polynomial extensively.

BRST deformations and stability in the higher derivative Chern–Simons gauge theory

We show the procedure of BRST deformations of the free Chern–Simons gauge theory with the higher derivatives in antifield formalism and obtain the consistent interactions in the master action at different orders. The key ingredient in our analysis is the local BRST-cohomology which plays a crucial role in the determination of the first-order deformation, also the Jacobi identity is needed since it will greatly simplify the calculations for us. Making using of the Dirac’s method, we give a detailed Hamiltonian analysis both for the free and interacting systems and exhibit that the number of physical degrees of freedom is unchanged after the deformation process. Moreover, we demonstrate that the free higher derivative system can be stabilized from the viewpoint of the existence of another bounded conserved quantities which are different from the canonical energy.

Merger-inspired rotation laws and the low-T/W instability in neutron stars

ABSTRACTImplementing a family of differential rotation laws inspired by binary neutron-star merger remnants, we consider the impact of the rotation profile on the low-T/W instability. We use time evolutions of the linearized dynamical equations, in Newtonian gravity, to study non-axisymmetric oscillations and identify the unstable modes. The presence and evolution of the low-T/W instability is monitored with the canonical energy and angular momentum, while the growth time is extracted from the evolved kinetic energy. The results for the new rotation laws highlight similarities with the commonly considered j-constant law. The instability sets in when an oscillation mode corotates with the star (i.e. whenever there is a point at which the mode’s pattern speed matches the bulk angular velocity) and grows faster deep inside the co-rotation region. However, the new profiles add features, like an additional co-rotation point, to the problem, and these affect the onset of instability. The rotation laws have the most drastic influence on the oscillation frequencies of the l = m = 2 f mode in fast-rotating models, but affect the instability growth time at some level for any rotation rate. We also identify models where the low-T/W instability appears to be triggered by inertial modes. We discuss to what extent the inferred qualitative behaviour is likely to be of observational relevance.

Mass formulae and staticity condition for dark matter charged black holes

The Arnowitt–Deser–Misner formalism is used to derive variations of mass, angular momentum and canonical energy for Einstein–Maxwell dark matter gravity in which the auxiliary gauge field coupled via kinetic mixing term to the ordinary Maxwell one, which mimics properties of hidden sector. Inspection of the initial data for the manifold with an interior boundary, having topology of S^2, enables us to find the generalised first law of black hole thermodynamics in the aforementioned theory. It has been revealed that the stationary black hole solution being subject to the condition of encompassing a bifurcate Killing horizon with a bifurcation sphere, which is non-rotating, must be static and has vanishing magnetic Maxwell and dark matter sector fields, on static slices of the spacetime under consideration.

Characteristics of Atmospheric Kinetic Energy Spectra during the Intensification of Typhoon Lekima (2019)

The intensification of Typhoon Lekima (2019) is simulated with the Weather Research and Forecasting model to study the atmospheric horizontal kinetic energy (HKE) spectra and corresponding spectral HKE budgets under the control of real tropical cyclone (TC). The results show that the TC has the ability to modify the canonical atmospheric energy spectrum during its evolution, which is dominated by its rotational mode. With the intensification of Lekima, the HKE spectrum in the troposphere swells over the central mesoscale and develops an arc-like shape. The stronger the TC, the more pronounced the arc-like shape is and the smaller scale it extends to. The roles various physical processes play at different heights and horizontal scales during the intensification of Lekima are investigated and the dependence of the effect of physical processes on scale and height is revealed. Meanwhile, the potential relationship between the intensification of TC, the activation of energy activity at smaller scales, and the downscale extension of the arc-like spectral shape is found.

Energy-Momentum Relocalization, Surface Terms, and Massless Poles in Axial Current Matrix Elements

The energy-momentum relocalization in classical and quantum theory is addressed with specific impact on non-perturbative QCD and hadronic structure. The relocalization is manifested in the existence of canonical and symmetric (Belinfante and Hilbert) energy momentum tensors (EMT). The latter describes the interactions of hadrons with classical gravity and inertia. Canonical EMT, in turn, is naturally emerging due to the translation invariance symmetry and appears when spin structure of hadrons is considered. Its relation to symmetric Hilbert and Belinfante EMTs requires the possibility to neglect the contribution of boundary terms for the classical fields. For the case of quantum fields this property corresponds to the absence of zero-momentum poles of matrix element of the axial current dual to the spin density. This property is satisfied for quarks manifesting the symmetry counterpart of UA(1) problem and may be violated for gluons due to QCD ghost pole.

Dihydroxyacetone phosphate signals glucose availability to mTORC1.

The mTOR complex 1 (mTORC1) kinase regulates cell growth by setting the balance between anabolic and catabolic processes. To be active, mTORC1 requires the environmental presence of amino acids and glucose. While a mechanistic understanding of amino acid sensing by mTORC1 is emerging, how glucose activates mTORC1 remains mysterious. Here, we used metabolically engineered human cells lacking the canonical energy sensor AMPK to identify glucose-derived metabolites required to activate mTORC1 independent of energetic stress. We show that mTORC1 senses a metabolite downstream of the aldolase and upstream of the glyceraldehyde 3-phosphate dehydrogenase steps of glycolysis and pinpoint dihydroxyacetone phosphate (DHAP) as the key molecule. In cells expressing a triose kinase, the synthesis of DHAP from dihydroxyacetone is sufficient to activate mTORC1 even in the absence of glucose. DHAP is a precursor for lipid synthesis, a process under the control of mTORC1, which provides a potential rationale for the sensing of DHAP by mTORC1.

Function of Dicer with regard to Energy Homeostasis Regulation, Structural Modification, and Cellular Distribution.

As a type III ribonuclease (RNase III) specifically cleaving double-stranded RNA substrates into short fragments, Dicer is indispensable in a range of physi/pathologic processes, e.g., nutrient deprivation, hypoxia, or DNA damage. Therefore, much interest has been paid to the research of this protein as well as its products like microRNAs (miRNAs). The close relationship between Dicer levels and fluctuations of nutrient availability suggests that the protein participates in the regulation of systemic energy homeostasis. Through miRNAs, Dicer regulates the hypothalamic melanocortin-4 system and central autophagy promoting energy expenditure. Moreover, by influencing canonical energy sensors like adenosine monophosphate-activated protein kinase (AMPK) or mammalian target of rapamycin (mTOR), Dicer favors catabolism in the periphery. Taken together, Dicer might be targeted in the control of energy dysregulation. However, factors affecting its RNase activity should be noted. Firstly, modulation of structural integrity affects its role as a ribonuclease. Secondly, although previously known as a cytosolic endoribonuclease, evidence suggests Dicer can relocalize into the nucleus where it could also produce small RNAs. In this review, we probe into involvement of Dicer in energy homeostasis as well as its structural integrity or cellular distribution which affects its ability to produce miRNAs, in the hope of providing novel insights into its mechanism of action for future application.

An energy decomposition analysis approach to the rotational barriers of amides and thioamides

The most popular interpretation for the origin of rotational barrier in amides is the electron delocalization of the nitrogen lone pair over the NCO π system. Many attempts have been made to quantify the extent of delocalization in amide and amide like systems. An alternative approach to understand rotational barriers is the energy decomposition analysis (EDA) class of methods. In this work, the rotational barrier of a series of amides is investigated using the Canonical Molecular Orbital Energy Decomposition Analysis (CMOEDA) method. Based on CMOEDA, it was possible to explain i) the origin of the rotational barriers, ii) the energy difference between the two transition states (TS1/TS2) and iii) the variation in the rotational barrier as structural modifications are introduced. Regarding the origin of the rotational barrier, for instance, it was verified that electrostatic and polarization interactions are responsible for building the barrier, while exchange-repulsion contributes to decrease its value.

Resonance and stability of higher derivative theories of a derived type

We consider the class of higher derivative field equations whose wave operator is a square of another self-adjoint operator of lower order. At the free level, the models of this class are shown to admit a two-parameter series of integrals of motion. The series includes the canonical energy. Every conserved quantity is unbounded in this series. The interactions are included into the equations of motion such that a selected representative in conserved quantity series is preserved at the non-linear level. The interactions are not necessarily Lagrangian, but they admit Hamiltonian form of dynamics. The theory is stable if the integral of motion is bounded from below due to the interaction. The motions are finite in the vicinity of the conserved quantity minimum. The equations of motion for fluctuations have the derived form with no resonance. The general constructions are exemplified by the models of the Pais-Uhlenbeck oscillator with multiple frequency and Podolsky electrodynamics. The example is also considered of stable non-abelian Yang-Mills theory with higher derivatives.

Perturbative expansions of R\xe9nyi relative divergences and holography

In this paper, we develop a novel way to perturbatively calculate Rényi relative divergences Dγ(ρ‖σ) = trργσ1 − γ and related quantities without using replica trick as well as analytic continuation. We explicitly determine the form of the perturbative term at any order by an integral along the modular flow of the unperturbed state. By applying the prescription to a class of reduced density matrices in conformal field theory, we find that the second order term of certain linear combination of the divergences has a holographic expression in terms of bulk symplectic form, which is a one parameter generalization of the statement “Fisher information = Bulk canonical energy”.

Instabilities and Multiscale Interactions Underlying the Loop Current Eddy Shedding in the Gulf of Mexico

AbstractA recently developed tool, the multiscale window transform, along with the theory of canonical energy transfer is used to investigate the roles of multiscale interactions and instabilities in the Gulf of Mexico Loop Current (LC) eddy shedding. A three-scale energetics framework is employed, in which the LC system is reconstructed onto a background flow window, a mesoscale eddy window, and a high-frequency eddy window. The canonical energy transfer between the background flow and the mesoscale windows plays an important role in LC eddy shedding. Barotropic instability contributes to the generation/intensification of the mesoscale eddies over the eastern continental slope of the Campeche Bank. Baroclinic instability favors the growth of the mesoscale eddies that propagate downstream to the northeastern portion of the well-extended LC, eventually causing the shedding by cutting through the neck of the LC. These upper-layer mesoscale eddies lose their kinetic energy back to the background LC through inverse cascade processes in the neck region. The deep eddies obtain energy primarily from the upper layer through vertical pressure work and secondarily from baroclinic instability in the deep layer. In contrast, the canonical energy transfer between the mesoscale and the high-frequency frontal eddy windows accounts for only a small fraction in the mesoscale eddy energy balance, and this generally acts as a damping mechanism for the mesoscale eddies. A budget analysis reveals that the mesoscale eddy energy gained through the instabilities is balanced by horizontal advection, pressure work, and dissipation.

Transcriptome analysis of breast cancer cell line exposed to hypoxia-mimetic chemical CoCl2 or hypoxic microenvironment

Hypoxia is a common feature of solid tumors, including breast cancer, and is related to aggressiveness and poor prognosis. The hypoxia-inducible factor 1, HIF-1, is the central transcriptional factor of response to hypoxia. Hypoxia-inducing methods, as low oxygen level and chemical compound cobalt(II) chloride (CoCl2) block HIF-1α degradation, that moves to the cell's nucleus and promotes the expression of its target genes. However, the effects on gene expression profiles driven by each hypoxia inducer are little known in breast cancer. This work aims to compare differential expression genes and pathways induced by CoCl2 or hypoxia chamber in MDA-MB-231 breast cancer cell line. Transcriptomes were conducted on Human Chip 1.0 exon from CoCl2-treated cells or hypoxic conditions. Differential gene expression profiles were clustered using DAVID and FunRich, to determine cellular components and signaling pathways. Both CoCl2 treatment and hypoxia chamber upregulated genes involved in response to hypoxia and downregulated genes clustered in FoxO signaling pathway, Wnt signaling pathway, Fanconi anemia pathway and non-homologous end-joining. Several canonical signaling pathways and energy metabolism were altered only after hypoxia chamber. CoCl2 altered glutathione, amino acid metabolism, endocytosis and PI3K-Akt genes. We observed greater amount of genes, cellular components and pathways altered after hypoxia chamber than CoCl2 treatment. The findings suggest that despite the similarities, CoCl2 treatment and hypoxia chamber also promote exclusive effects of each method. Then, depending of objective, they cannot be interchangeable, considering mainly gene expression studies that have as model MDA-MB-231 breast cancer cell line.

Near-Linear Scaling in DMRG-Based Tailored Coupled Clusters: An Implementation of DLPNO-TCCSD and DLPNO-TCCSD(T).

We present a new implementation of density matrix renormalization group based tailored coupled clusters method (TCCSD), which employs the domain-based local pair natural orbital approach (DLPNO). Compared to the previous local pair natural orbital (LPNO) version of the method, the new implementation is more accurate, offers more favorable scaling, and provides more consistent behavior across the variety of systems. On top of the singles and doubles, we include the perturbative triples correction (T), which is able to retrieve even more dynamic correlation. The methods were tested on three systems: tetramethyleneethane, oxo-Mn(Salen), and iron(II)-porphyrin model. The first two were revisited to assess the performance with respect to LPNO-TCCSD. For oxo-Mn(Salen), we retrieved between 99.8 and 99.9% of the total canonical correlation energy which is an improvement of 0.2% over the LPNO version in less than 63% of the total LPNO runtime. Similar results were obtained for iron(II)-porphyrin. When the perturbative triples correction was employed, irrespective of the active space size or system, the obtained energy differences between two spin states were within the chemical accuracy of 1 kcal/mol using the default DLPNO settings.

Representation of the virtual space in extended systems – a correlation energy convergence study

We present an investigation of the convergence behaviour of the local second-order Møller-Plesset perturbation theory (MP2) correlation energy toward the canonical result for three insulating crystals with either projected atomic orbitals (PAOs) or various orthonormal representations of the virtual orbital space. Echoing recent results for finite molecular systems, we find that significantly fewer PAOs than localised orthonormal virtual orbitals are required to reproduce the canonical correlation energy. We find no clear-cut correlation between conventional measures of orbital locality and the ability of the representation to span the excitation space of local domains. We show that the PAOs of the reference unit cell span parts of the excitation space that can only be reached with distant local orthonormal virtual orbitals.

ON THE PHYSICAL MEANING OF THE COEFFICIENT OF FRICTION UNDER CONDITIONS OF ABNORMALLY LOW FRICTION AND WEAR

The theoretical studies of tribosystems (TS) operating under conditions of abnormally low friction and wear are given. On the basis of the analysis of the mechanisms of dissipation of external energy, as factors of friction reduction in different areas of nature, the role of the wave component of friction force is clarified. Under certain thermodynamic conditions, a sufficiently large wave component of the friction force is formed in the TS, which significantly reduces the molecular-mechanical. The wave component Fw of the friction force Ffr is the «entropy pump» that converts the non-compensated external friction into the internal friction and accumulates the internal energy in the elastic-plastic layer of the rheological model of Shvedov tribosystem construction. The physical meaning of the friction coefficient for TS operating under conditions of normal mechanochemical wear and abnormally low friction and wear has been determined. It is determined that the main cause of the tribosystems transition to abnormally low friction and wear is the rheological properties of the tribosystem surface layer. In an anomalous-low friction and wear mode tribosystem, an equilibrium and inverse change of some insignificant amount of energy without work is possible. TS heat dissipation in this case approaches zero. When the external friction conditions change, the degree of excitation of tribosystem n, which depends on the number of mechanical quanta, changes. Any change in the tribosystem that puts it off balance, according to Le Chatelier principle, initiates in it processes that try to return it to its original position. For these processes in the developed model is responsible module of canonical energy distribution, which is regulated by microgeometry of the surface layer of TS. It is established that the condition of achieving abnormally low friction and wear is the equality of robots that perform external and internal forces in terms of contact interaction. Structural-energy approach to contact interaction allowed to establish the physical meaning of the coefficient of friction, which generally characterizes the work of external and internal forces in the path of friction tribosystems.

Noether currents of locally equivalent symmetries

Local symmetry transformations play an important role for establishing the existence and form of a conserved (Noether) current in systems with a global continuous symmetry. We explain how this fact leads to the existence of linear relations between Noether currents of distinct global symmetries that coincide on the local level, thus generalizing the well-known relationship between momentum and angular momentum . As a byproduct, we find a natural interpretation for the discrepancy between the canonical and metric energy–momentum (EM) tensors in theories of particles with spin. A symmetric EM tensor can thus be obtained from the Noether procedure without adding any ad hoc corrections or imposing additional constraints such as gauge invariance in Maxwell’s electrodynamics.

Wetting transitions on soft substrates

Within mean-field theory we study wetting of elastic substrates. Our analysis is based on a grand canonical free energy functional of the fluid number density and of the substrate displacement field. The substrate is described in terms of the linear theory of elasticity, parametrized by two Lamé coefficients. The fluid contribution is of the van der Waals type. Two potentials characterize the interparticle interactions in the system. The long-ranged attraction between the fluid particles is described by a potential , and characterizes the substrate-fluid interaction. By integrating out the elastic degrees of freedom we obtain an effective theory for the fluid number density alone. Its structure is similar to the one for the wetting of an inert substrate. However, the potential is replaced by an effective potential which, in addition to , contains a term bilinear in . We discuss the corresponding wetting transitions in terms of an effective interface potential , where ℓ denotes the thickness of the wetting layer. We show that in the case of algebraically decaying interactions the elasticity of the substrate may suppress critical wetting transitions, and may even turn them first order.

An efficient computational procedure to obtain a more stable glass structure.

A huge gap in time between the experiment and the atomistic simulation restricts us from accessing a realistic glass structure, because the glass state is highly dependent on the cooling rate. In this study, to improve computational efficiency, we propose a simple but effective procedure, which enables us to explore a deeper basin in the energy landscape of glassy materials without a substantial increase in the computational cost. This method combines canonical ensemble molecular dynamics (MD) and energy minimization while controlling the stress of the MD system, and it is called the quasi-slow-quenching (QSQ) method. Herein, we measured the performance of the QSQ method using a binary silicate, (SiO2)80(Na2O)20, and we observed that a more stable configuration can be obtained in comparison with the conventional isobaric-isothermal MD method. The stable glass model appears to possess a lower glass transition temperature (Tg), confirming that the QSQ method finds a deeper local minimum closer to the super-cooled glass state. We also conducted further validation tests for various oxide glasses, including silicate, borate, phosphate, and their mixtures, and we verified that the QSQ method consistently enables the glassy materials to attain energetically more stable configurations and denser structures.