14 research outputs found
Physical States, Factorization and Nonlinear Structures in Two Dimensional Quantum Gravity
The nonlinear structures in 2D quantum gravity coupled to the
minimal model are studied in the Liouville theory to clarify the factorization
and the physical states. It is confirmed that the dressed primary states
outside the minimal table are identified with the gravitational descendants.
Using the discrete states of ghost number zero and one we construct the
currents and investigate the Ward identities which are identified with the W
and the Virasoro constraints. As nontrivial examples we derive the ,
and equations exactly. and equations are also
discussed. We then explicitly show the decoupling of the edge states . We consider the interaction theory perturbed by the
cosmological constant and the screening charge . The
formalism can be easily generalized to potential models other than the
screening charge.Comment: 18 pages, LaTex, YITP/U-93-2
Non-linear Structures in Non-critical NSR String
We investigate the Ward identities of the \W_{\infty} symmetry in the
super-Liouville theory coupled to the super-conformal matter of central charge
. The theory is classified into two chiralities.
For the positive chirality, all gravitationally dressed scaling operators are
generated from the gravitational primaries by acting one of the ring
generators in the R-sector on them repeatedly. After fixing the normalizations
of the dressed scaling operators, we find that the Ward identities are
expressed in the form of the {\it usual} \W_q algebra constraints as in the
bosonic case: \W^{(k+1)}_n \tau =0, , where the equations for even and odd come from the currents in the
NS- and the R-sector respectively. The non-linear terms come from the anomalous
contributions at the boundaries of moduli space. The negative chirality is
defined by interchanging the roles of and . Then we get the \W_p
algebra constraints.Comment: 22 pages, Latex file, YITP/U-94-16, UT-Komaba/94-1
Ward Identities of W_{\infty} Symmetry and Higher Genus Amplitudes in 2D String Theory
The Ward identities of the symmetry in two dimensional string
theory in the tachyon background are studied in the continuum approach. We
consider amplitudes different from 2D string ones by the external leg factor
and derive the recursion relations among them. The recursion relations have
non-linear terms which give relations among the amplitudes defined on different
genus. The solutions agree with the matrix model results even in higher genus.
We also discuss differences of roles of the external leg factor between the
model and the model.Comment: 21 pages, Latex, 5 figures. Revised version published in Nucl. Phys.
B. Errors of coefficients in some formula and the potential term are
corrected. Some sentences are rewritte
Background-metric Independent Formulation of 4D Quantum Gravity
Using the background-metric independence for the traceless mode as well as
the conformal mode, 4D quantum gravity is described as a quantum field theory
defined on a non-dynamical background-metric. The measure then induces an
action with 4 derivatives. So we think that 4-th order gravity is essential and
the Einstein-Hilbert term should be treated like a mass term. We introduce the
dimensionless self-coupling constant t for the traceless mode. In this paper we
study a model where the measure can be evaluated in the limit
exactly, using the background-metric independence for the conformal mode. The
t-dependence of the measure is determined perturbatively using the
background-metric independence for the traceless mode.Comment: 27 pages, references added, some sentences added and corrected
especially in sect.3 and 6; version to appear in Nucl. Phys.
The Lantern Vol. 36, No. 1, Winter 1970
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Recursion Relations in Liouville Gravity coupled to Ising Model satisfying Fusion Rules
The recursion relations of 2D quantum gravity coupled to the Ising model
discussed by the author previously are reexamined. We study the case in which
the matter sector satisfies the fusion rules and only the primary operators
inside the Kac table contribute. The theory involves unregularized divergences
in some of correlators. We obtain the recursion relations which form a closed
set among well-defined correlators on sphere, but they do not have a beautiful
structure that the bosonized theory has and also give an inconsistent result
when they include an ill-defined correlator with the divergence. We solve them
and compute the several normalization independent ratios of the well-defined
correlators, which agree with the matrix model results.Comment: Latex, 22 page
Vertex Operators in 4D Quantum Gravity Formulated as CFT
We study vertex operators in 4D conformal field theory derived from quantized
gravity, whose dynamics is governed by the Wess-Zumino action by Riegert and
the Weyl action. Conformal symmetry is equal to diffeomorphism symmetry in the
ultraviolet limit, which mixes positive-metric and negative-metric modes of the
gravitational field and thus these modes cannot be treated separately in
physical operators. In this paper, we construct gravitational vertex operators
such as the Ricci scalar, defined as space-time volume integrals of them are
invariant under conformal transformations. Short distance singularities of
these operator products are computed and it is shown that their coefficients
have physically correct sign. Furthermore, we show that conformal algebra holds
even in the system perturbed by the cosmological constant vertex operator as in
the case of the Liouville theory shown by Curtright and Thorn.Comment: 26 pages, rewrote review part concisely, added explanation
Renormalizable 4D Quantum Gravity as A Perturbed Theory from CFT
We study the renormalizable quantum gravity formulated as a perturbed theory
from conformal field theory (CFT) on the basis of conformal gravity in four
dimensions. The conformal mode in the metric field is managed
non-perturbatively without introducing its own coupling constant so that
conformal symmetry becomes exact quantum mechanically as a part of
diffeomorphism invariance. The traceless tensor mode is handled in the
perturbation with a dimensionless coupling constant indicating asymptotic
freedom, which measures a degree of deviation from CFT. There are no massive
ghosts because they are not gauge invariant in this formulation. Higher order
renormalization is carried out using dimensional regularization, in which the
Wess-Zumino integrability condition is applied to reduce indefiniteness
existing in higher-derivative actions. The effective action of quantum gravity
improved by renormalization group is obtained. We then make clear that
conformal anomalies are indispensable quantities to preserve diffeomorphism
invariance. Anomalous scaling dimensions of the cosmological constant and the
Planck mass are calculated. The effective cosmological constant is obtained in
the large number limit of matter fields.Comment: 51 pages, 12 figure
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570