Integracija in transformacija: študija motivov sonca in lune pri upodobitvi Fuxija in Nüwe

The present research focuses on the depiction of the sun and moon in the imagery of Fuxi and Nüwa during the Han and Wei-Jin periods. Through typological and iconographical approaches, it proposes four primary modes in terms of the ways in which the sun and the moon are combined with Fuxi and Nüwa. It contributes to the current field by providing new perspectives for readdressing some issues that remain underexplored. First, it challenges the over-absolute identification of the earliest representation of Fuxi and Nüwa in a pair, and that of Changyi and Xihe, another set of paired deities recorded to be in close relation to the celestial world, in Western Han mural tombs from the Luoyang area, and instead suggests a shift of focus to the recognisable distinctions in visual details, such as the chronological sequence of the application of the first and second modes in the Luoyang Han tomb paintings, and the masculine appearances of both the deities depicted in the Western Han Qianjingtou tomb. Further examinations of the development and dissemination of each mode through the Han and Wei-Jin eras reveals complicated interactions between different regions and exchanges of motif with other forms of imagery. The local tradition of depicting Fuxi and Nüwa, together with that of the depiction of the sun and moon in Nanyang, has been incorporated into the formation of the sun and moon in anthropomorphic representations in the Southwest. Finally, this research proposes that it is more significant to organise the surviving materials through the development and context of each visual element represented in the scene, rather than making an absolute identification based on scattered evidence.Pričujoča razprava se osredotoča na motiv sonca in lune pri upodobitvi Fuxija in Nüwe v času dinastij Han in Wei Jin. Na osnovi tipološkega in ikonografskega pristopa predlaga štiri osnovne modele upodobitve sonca in lune v odnosu do Fuxija in Nüwe, s čimer izpostavi nove vidike za ponovno prevrednotenje nekaterih nenaslovljenih vprašanj. Najprej postavlja pod vprašaj absolutno identifikacijo najzgodnejše upodobitve Fuxija in Nüwe ter Changyi in Xihe, še enega para božanstev, povezanih z nebeškim svetom, ki jih najdemo v grobnicah s poslikavo v mestu Luoyang iz časa dinastije Zahodni Han. Pri tem predlaga preusmeritev pozornosti na prepoznavne razlike v vizualnih podrobnostih, kot jih lahko zaznamo v kronološkem zaporedju uporabe prvega in drugega modela v grobnicah iz mesta Luoyang ter v bolj možatem videzu obeh božanstev v grobnici Qiangjingtou iz časa Zahodnega Hana. Nadaljnje proučevanje razvoja in širitve posameznih modelov v dinastijah Han in Wei Jin prikaže kompleksne povezave med različnimi regijami ter izmenjave motiva z ostalimi podobami. Lokalna tradicija upodobitve Fuxija in Nüwe skupaj s prikazom sonca in lune iz kraja Nanyang je bila na primer vključena v oblikovanje podobe sonca in lune kot antropomorfične reprezentacije, ki je postala opazna zlasti v jugozahodnem delu kitajskega območja. Pričujoči prispevek v zaključku tudi poudari pomembnost obravnave ohranjene materialne dediščine prek razvoja ter vključitve posameznih vizualnih elementov v celotne prizore in ne zgolj formiranja absolutne identifikacije na podlagi posameznih dokazov

Proof of a Stable Fixed Point for Strongly Correlated Electron Matter

We establish the Hatsugai-Kohmoto model as a stable quartic fixed point (distinct from Wilson-Fisher) by computing the $\beta-$function in the presence of perturbing local interactions. In vicinity of the half-filled doped Mott state, the $\beta-$function vanishes for all local interactions regardless of their sign. The only flow away from the HK model is through the superconducting channel which lifts the spin degeneracy as does any ordering tendency. The superconducting instability is identical to that established previously\cite{nat1}. A corollary of this work is that Hubbard repulsive interactions flow into the HK stable fixed point in the vicinity of half-filling. Consequently, although the HK model has all-to-all interactions, nothing local destroys it. The consilience with Hubbard arises because both models break the $Z_2$ symmetry on a Fermi surface, the HK model being the simplest to do so. Indeed, the simplicity of the HK model belies its robustness and generality

Failure of Topological Invariants in Strongly Correlated Matter

We show exactly that standard `invariants' advocated to define topology for non-interacting systems deviate strongly from the Hall conductance whenever the excitation spectrum contains zeros of the single-particle Green function, $G$, as in general strongly correlated systems. Namely, we show that if the chemical potential sits atop the valence band, the `invariant' changes without even accessing the conduction band but by simply traversing the band of zeros that might lie between the two bands. Since such a process does not change the many-body ground state, the Hall conductance remains fixed. This disconnect with the Hall conductance arises from the replacement of the Hamiltonian, h(\bb k), with $G^{-1}$ in the current operator, thereby laying plain why perturbative arguments fail

Thermodynamics of an Exactly Solvable Model for Superconductivity in a Doped Mott Insulator

Computing superconducting properties starting from an exactly solvable model for a doped Mott insulator stands as a grand challenge. We have recently shown that this can be done starting from the Hatsugai-Kohmoto (HK) model which can be understood generally as the minimal model that breaks the non-local $\mathbb Z_2$ symmetry of a Fermi liquid, thereby constituting a new quartic fixed point for Mott physics [Phillips et al., Nature Physics 16, 1175 (2020); Huang et al., Nature Physics (2022)]. In the current work, we compute the thermodynamics, condensation energy, and electronic properties such as the NMR relaxation rate $1/T_1$ and ultrasonic attenuation rate. Key differences arise with the standard BCS analysis from a Fermi liquid: 1) the free energy exhibits a local minimum at $T_p$ where the pairing gap turns on discontinuously above a critical value of the repulsive HK interaction, thereby indicating a first-order transition, 2) a tri-critical point emerges, thereby demarcating the boundary between the standard second-order superconducting transition and the novel first-order regime, 3) Mottness changes the sign of the quartic coefficient in the Landau-Ginzburg free-energy fuctional relative to that in BCS, 4) as this obtains in the strongly interacting regime, it is Mott physics that underlies the generic first-order transition, 5) the condensation energy exceeds that in BCS theory suggesting that multiple Mott bands might be a way of enhancing superconducting, 6) the heat-capacity jump is non-universal and increases with the Mott scale, 7) Mottness destroys the Hebel-Slichter peak in NMR, and 8) Mottness enhances the fall-off of the ultrasonic attenuation at the pairing temperature $T_p$. As several of these properties are observed in the cuprates, our analysis here points a way forward in computing superconducting properties of strongly correlated electron matter.Comment: accepted in PR

1/4 is the new 1/2: Interaction-induced Unification of Quantum Anomalous and Spin Hall Effects

We introduce interactions into two general models for quantum spin Hall physics. Although the traditional picture is that such physics appears when the two lower spinful bands are occupied, that is, half-filling, we show using determinantal quantum Monte Carlo as well as from an exactly solvable model that in the presence of strong interactions, the quarter-filled state instead exhibits the quantum spin Hall effect at high temperature. A topological Mott insulator is the underlying cause. The peak in the spin susceptibility is consistent with a possible ferromagnetic state at $T=0$. The onset of such magnetism would convert the quantum spin Hall to a quantum anomalous Hall effect. We argue that it is the consistency with the Lieb-Schultz-Mattis theorem\cite{lsm1,lsm2} for interacting systems with an odd number of charges per unit cell that underlies the emergence of the quantum anomalous Hall effect as a low-temperature symmetry-broken phase of the quantum spin Hall effect. While such a symmetry-broken phase typically is accompanied by a gap, we find that the interaction strength must exceed a critical value for the gap to form using quantum Monte Carlo dynamical cluster approximation simulations. Hence, we predict that topology can obtain in a gapless phase but only in the presence of interactions in dispersive bands. These results are applied to recent experiments on moir\'e systems and shown to be consistent with valley-coherent quantum anomalous Hall physics.Comment: Figure 4e,f added as well as a referenc

Topological Phase Transition without Single-Particle-Gap Closing in Strongly Correlated Systems

We show here that numerous examples abound where changing topology does not necessarily close the bulk insulating charge gap as demanded in the standard non-interacting picture. From extensive determinantal and dynamical cluster quantum Monte Carlo simulations of the half-filled and quarter-filled Kane-Mele-Hubbard model, we show that for sufficiently strong interactions at either half- or quarter-filling, a transition between topological and trivial insulators occurs without the closing of a charge gap. To shed light on this behavior, we illustrate that an exactly solvable model reveals that while the single-particle gap remains, the many-body gap does in fact close. These two gaps are the same in the non-interacting system but depart from each other as the interaction turns on. We purport that for interacting systems, the proper probe of topological phase transitions is the closing of the many-body rather than the single-particle gap

Steroid saponins and other constituents from the rhizome of Trillium tschonoskii Maxim and their cytotoxic activity

Fourteen compounds were isolated from the rhizome of Trillium tschonoskii Maxim. By spectroscopic analysis, these compounds were established as Gracillin (1), Paris saponins V (2), Paris saponins VI (3), Paris saponins H (4), Paris saponins VII (5), (25R)-17α-hydroxy-5-en-3-O-a-L-arabinofuranosyl-(1→2)-β-Dglucopyranoside (6), (25R)-26-[β-D-glucopyanosyl]-17α,22β-dihydroxy-5-en-3-O-a-L-rhamnopyranosyl- (1→2)-β-D-glucopyranoside (7), Kaempferol-3-O-β-D-rutinoside (8), Quercetin (9), Quercetin-3-O-β-D-galactoside (10), Daucosterol (11), Stigmasterol-3-O-β-D-glucopyranoside (12), 3, 5-Di-O-caffeoyl quinic acid (13), and n-Hexadecanoic acid (14). By GC-MS analysis of the CH2Cl2 extract from Trillium tschonoskii Maxim, twenty compouns were identified, representing 91 % of the area. The cytotoxicity of compounds 1-14 on mouse A549 cells were evaluated.Colegio de Farmacéuticos de la Provincia de Buenos Aire