Gaussian models with finitely many matrices are the most well studied.

## Quantum Physics May Be Even Spookier Than You Think

However certain ensembles with growing number of matrices such as lattice gauge theories have been studied in the physics literature as discrete approximations to Euclidean Yang-Mills theory for a long time. We will review the recent work of Chatterjee who rigorously established a gauge-string duality in a class of such models and discuss attempts at analyzing the associated string trajectories.

Nam-Gyu Kang Calculus of conformal fields on a compact Riemann surface [slides] Thanks to Eguchi and Ooguri, it is known that the insertion of a stress tensor acts within correlations of fields in the OPE family according to the Lie derivative operator along a certain vector field and a certain differential operator with respect to the modular parameters.

After presenting analytical implementation of conformal field theory on a compact Riemann surface, I explain how to derive Eguchi-Ooguri's version of Ward's equation on a torus from the pseudo-addition theorem for Weierstrass zeta function and present some examples. Joint work with N. The CFT description has in particular lead to exact and correct albeit mostly non-rigorous predictions of critical exponents and scaling limit correlation functions in many lattice models.

The main ingredient of CFT is the Virasoro algebra, accounting for the effect of infinitesimal conformal transformations on local fields. In this talk we show that an exact Virasoro algebra action exists on the probabilistic local fields of two discrete models: the discrete Gaussian free field and the critical Ising model on the square lattice.

In particular, the model shows connections with the theory of isomonodromy deformations developed by Sato, Miwa and Jimbo. Joint work with SC Park. Since photons have the rest mass zero, and correspondingly travel in the vacuum at the velocity, naturally, of light c it is ruled out that a non-relativistic theory such as ordinary QM could give even an approximate description. Photons are implicitly contained in the emission and absorption processes which have to be postulated, for instance, when one of an atom's electrons makes a transition from a higher to a lower energy level or vice versa.

However, only the formalism of QFT contains an explicit description of photons. In fact most topics in the early development of quantum theory — were related to the interaction of radiation and matter and should be treated by quantum field theoretical methods. As soon as the conceptual framework of quantum mechanics was developed, a small group of theoreticians immediately tried to extend the methods to electromagnetic fields. A good example is the famous three-man paper by M.

Born, W. Heisenberg, and P. Jordan Especially P. Jordan was acquainted with the literature on light quanta and made important contributions to QFT. The basic analogy was that in QFT field quantities, i.

The ideas of QM were extended to systems having an infinite number of degrees of freedom. Dirac supplied a systematic procedure for transferring the characteristic quantum phenomenon of discreteness of physical quantities from the quantum mechanical treatment of particles to a corresponding treatment of fields.

### Go from Quantum to Cosmic

Employing the quantum mechanical theory of the harmonic oscillator, Dirac gave a theoretical description of how photons appear in the quantization of the electromagnetic radiation field. Later, Dirac's procedure became a model for the quantization of other fields as well. During the following three years the first approaches to QFT were further developed. Jordan introduced creation operators for fields obeying Fermi statistics. For an elementary discussion of quantum statistics Fermi and Bose , see the entry on quantum theory: identity and individuality.

So the methods of QFT could be applied to equations resulting from the quantum mechanical field like treatment of particles like the electron e.

## Current Developments in Quantum Field Theory and Gravity

Schweber points out Schweber , p. Some difficult problems concerning commutation relations, statistics and Lorentz invariance could be solved.

Fermi and Dirac, Fock and Podolski presented different formulations which played a heuristic role in the following years. The first pillar results from the quantization of the electromagmetic field, i.

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This procedure will be described in some more detail in the section on the particle interpretation. The second pillar of QED consists in the relativistic theory of the electron, with the Dirac equation in its centre. Quantum field theory started with a theoretical framework that was built in analogy to quantum mechanics.

Although there was no unique and fully developed theory, quantum field theoretical tools could be applied to concrete processes. Calculations to the first order of approximation were quite successful, but most people working in the field thought that QFT still had to undergo a major change. Citing Article s :. Oxford Academic. Google Scholar. Cite Citation. Permissions Icon Permissions. Abstract Throughout the course of its development in the past four decades quantum field theory has gradually acquired a very rich structure much richer in fact than it was originally intended and now provides us with an effective method in the analysis of many diverse areas of physics; condensed matter physics, high energy particle physics general relativity and cosmology are among the more notable examples.

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