scholarly journals On the Definition of the Partition Function in Quantum Regge Calculus

1995 ◽  
Vol 94 (2) ◽  
pp. 299-304 ◽  
Author(s):  
J. Nishimura
Author(s):  
Arkady A. Tseytlin

We discuss possible definition of open string path integral in the presence of additional boundary couplings corresponding to the presence of masses at the ends of the string. These couplings are not conformally invariant implying that as in a non-critical string case one is to integrate over the one-dimensional metric or reparametrizations of the boundary. We compute the partition function on the disc in the presence of an additional constant gauge field background and comment on the structure of the corresponding scattering amplitudes.


1994 ◽  
Vol 05 (02) ◽  
pp. 359-361 ◽  
Author(s):  
W. BEIRL ◽  
H. MARKUM ◽  
J. RIEDLER

Quantum gravity is studied in the path integral formulation applying the Regge calculus. Restricting the quadratic link lengths of the originally triangular lattice the path integral can be transformed to the partition function of a spin system with higher couplings on a Kagomé lattice. Various measures acting as external field are considered. Extensions to matter fields and higher dimensions are discussed.


2021 ◽  
Vol 9 ◽  
Author(s):  
Nadir Fasola ◽  
Sergej Monavari ◽  
Andrea T. Ricolfi

Abstract We exploit the critical structure on the Quot scheme $\text {Quot}_{{{\mathbb {A}}}^3}({\mathscr {O}}^{\oplus r}\!,n)$ , in particular the associated symmetric obstruction theory, in order to study rank r K-theoretic Donaldson-Thomas (DT) invariants of the local Calabi-Yau $3$ -fold ${{\mathbb {A}}}^3$ . We compute the associated partition function as a plethystic exponential, proving a conjecture proposed in string theory by Awata-Kanno and Benini-Bonelli-Poggi-Tanzini. A crucial step in the proof is the fact, nontrival if $r>1$ , that the invariants do not depend on the equivariant parameters of the framing torus $({{\mathbb {C}}}^\ast )^r$ . Reducing from K-theoretic to cohomological invariants, we compute the corresponding DT invariants, proving a conjecture of Szabo. Reducing further to enumerative DT invariants, we solve the higher rank DT theory of a pair $(X,F)$ , where F is an equivariant exceptional locally free sheaf on a projective toric $3$ -fold X. As a further refinement of the K-theoretic DT invariants, we formulate a mathematical definition of the chiral elliptic genus studied in physics. This allows us to define elliptic DT invariants of ${{\mathbb {A}}}^3$ in arbitrary rank, which we use to tackle a conjecture of Benini-Bonelli-Poggi-Tanzini.


1982 ◽  
Vol 14 (8) ◽  
pp. 1031-1046 ◽  
Author(s):  
R G V Baker

The definition of place utility from potential theory shows that a preference and orthogonal indifference field can influence a decisionmaker, which suggests the operation of behavioural forces. Learning energy is defined to be a major behavioural force and a statistical model is proposed for its distribution over an assembly of decisionmakers. An attitude system is derived for a social network where the decisionmaker can be in a unitary state of utility or disutility. The resulting partition function shows that the learning energy of the assembly is derived from nearest-neighbour interactions and the operation of an external place utility preference field. A positive linear relationship is proposed between learning energy and environmental stress. The critical stress in social interaction is determined and a variety of behaviours in urban sociology are predicted. The model is then applied to a Markov learning system and the results discussed.


2016 ◽  
Author(s):  
Gassan Nazzal

Abstract.In this work, we attempt to determine the assumptions of each case of the QSSA. We came to the conclusion that for an enzyme with average kinetics parameters the REA is a good approximation to derive the rate equation and the Km value tends to equal the dissociation constant Kd. The active site classifies the population of the substrate into two energy states, the ground state, and the transition state. The ratio Km/Kd is equal to the partition function of the assumed two-state-system. For the average enzyme, the partition function of the transition tends to equal 1 thus the majority of the substrate molecules are in the ground state and the assumption kcat << k−1 is valid hence Km ≈ Kd. In contrast, when the enzyme is diffusion controlled, the Km value is equal to the productive dissociation rate kcat/k1. We have also redefined the Km value as the equivalence point of the reaction rates, namely, the effective diffusion rate and the maximal catalytic rate, which reflects more clearly the transition from the bimolecular reaction to the unimolecular reaction in the saturation curve.


1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.


1975 ◽  
Vol 26 ◽  
pp. 21-26

An ideal definition of a reference coordinate system should meet the following general requirements:1. It should be as conceptually simple as possible, so its philosophy is well understood by the users.2. It should imply as few physical assumptions as possible. Wherever they are necessary, such assumptions should be of a very general character and, in particular, they should not be dependent upon astronomical and geophysical detailed theories.3. It should suggest a materialization that is dynamically stable and is accessible to observations with the required accuracy.


1979 ◽  
Vol 46 ◽  
pp. 125-149 ◽  
Author(s):  
David A. Allen

No paper of this nature should begin without a definition of symbiotic stars. It was Paul Merrill who, borrowing on his botanical background, coined the termsymbioticto describe apparently single stellar systems which combine the TiO absorption of M giants (temperature regime ≲ 3500 K) with He II emission (temperature regime ≳ 100,000 K). He and Milton Humason had in 1932 first drawn attention to three such stars: AX Per, CI Cyg and RW Hya. At the conclusion of the Mount Wilson Ha emission survey nearly a dozen had been identified, and Z And had become their type star. The numbers slowly grew, as much because the definition widened to include lower-excitation specimens as because new examples of the original type were found. In 1970 Wackerling listed 30; this was the last compendium of symbiotic stars published.


Author(s):  
K. T. Tokuyasu

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).


Author(s):  
W. A. Shannon ◽  
M. A. Matlib

Numerous studies have dealt with the cytochemical localization of cytochrome oxidase via cytochrome c. More recent studies have dealt with indicating initial foci of this reaction by altering incubation pH (1) or postosmication procedure (2,3). The following study is an attempt to locate such foci by altering membrane permeability. It is thought that such alterations within the limits of maintaining morphological integrity of the membranes will ease the entry of exogenous substrates resulting in a much quicker oxidation and subsequently a more precise definition of the oxidative reaction.The diaminobenzidine (DAB) method of Seligman et al. (4) was used. Minced pieces of rat liver were incubated for 1 hr following toluene treatment (5,6). Experimental variations consisted of incubating fixed or unfixed tissues treated with toluene and unfixed tissues treated with toluene and subsequently fixed.


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