There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

To say that this is the best book on the quantum theory of fields is no praise, since to my knowledge it is the only book on this subject But it is a very good and most useful book The original was written in German and appeared in 1942 This is a translation with some minor changes A few remarks have been added, concerning meson theory and nuclear forces, also footnotes referring to modern work in this field, and finally an appendix on the symmetrization of the energy momentum tensor according to Belinfante Quantum Theory of Fields Prof Gregor Wentzel Translated from the German by Charlotte Houtermans and J M Jauch Pp ix + 224, (New York and London: Interscience Publishers, Inc, 1949) 36s

Quantum Theory of Fields

Superstring theoryをめぐって(放談室)

These notes are loosely based on lectures given at the CERN Winter School on Supergravity, Strings and Gauge theories, February 2009, and at the IPM String School in Tehran, April 2009. I have focused on a few concrete topics and also on addressing questions that have arisen repeatedly. Background condensed matter physics material is included as motivation and easy reference for the high energy physics community. The discussion of holographic techniques progresses from equilibrium, to transport and to superconductivity.

https://iopscience.iop.org/article/10.1088/0264-9381/26/22/224002/pdf

Lectures on holographic methods for condensed matter physics

We consider 6d $ \mathcal{N} = \left( {2,0} \right) $ theory on N M5-branes, together with a 4d defect labeled by a Young diagram Y specifying its global symmetry GY. A recent conjecture states that a compactification of this system leads to a 2d theory with W-algebra symmetry depending on Y. We provide a check of the conjecture by reproducing the level of the current subalgebra $ {\hat{G}_Y} $ of this W-algebra from the property of the 4d defect.

On W-algebras and the symmetries of defects of 6d $ \mathcal{N} = \left( {2,0} \right) $ theory

We point out that different choices of Gliozzi-Scherk-Olive (GSO) projections in superstring theory can be conveniently understood by the inclusion of fermionic invertible phases, or equivalently topological superconductors, on the worldsheet. This allows us to find that the unoriented Type $\rm 0$ string theory with $\Omega^2=(-1)^{\sf f}$ admits different GSO projections parameterized by $n$ mod 8, depending on the number of Kitaev chains on the worldsheet. The presence of $n$ boundary Majorana fermions then leads to the classification of D-branes by $KO^n(X)\oplus KO^{-n}(X)$ in these theories, which we also confirm by the study of the D-brane boundary states. Finally, we show that there is no essentially new GSO projection for the Type $\rm I$ worldsheet theory by studying the relevant bordism group, which classifies corresponding invertible phases. This paper provides the details for the results announced in the letter \cite{Kaidi:2019pzj}.

/pdf/topological-superconductors-on-superstring-worldsheets-2a4923az5c.pdf

Topological superconductors on superstring worldsheets

We construct a huge number of anomaly-free models of six-dimensional N = (1,0) gauged supergravity. The gauge groups are products of U(1) and SU(2), and every hyperino is charged under some of the gauge groups. It is also found that the potential may have flat directions when the R-symmetry is diagonally gauged together with another gauge group. In an appendix, we determine the contribution to the global SU(2) anomaly from symplectic Majorana Weyl fermions in six dimensions.

More anomaly-free models of six-dimensional gauged supergravity

We consider the low-energy limit of the two-dimensional theory on k M2-branes suspended between a straight M5-brane and a curved M5-brane. We argue that it is described by an N=(2,2) supersymmetric gauge theory with no matter fields but with a non-trivial twisted superpotential, and also by an N=(2,2) supersymmetric Landau-Ginzburg model, such that the (twisted) superpotentials are determined by the shape of the M5-branes. We find particular cases realize Kazama-Suzuki models. Evidence is provided by the study of ground states, chiral rings, BPS spectra and S^2 partition functions of the systems.

2d SCFTs from M2-branes

We point out that the USp symmetry associated to a full twisted puncture of a class S theory of type Aeven has the global anomaly associated to π4(USp) = ℤ2. We discuss manifestations of this fact in the context of the superconformal field theory R2,2N introduced by Chacaltana, Distler and Trimm. For example, we find that this theory can be thought of as a natural ultraviolet completion of an infrared-free SO(2N + 1) gauge theory with 2N flavors, whose USp(4N) symmetry clearly has the global anomaly.

/pdf/comments-on-the-twisted-punctures-of-aeven-class-s-theory-40gn1u2v26.pdf

Yuji Tachikawa

Papers

On W-algebras and the symmetries of defects of 6d \( \mathcal{N} = \left( {2,0} \right) \) theory

Topological superconductors on superstring worldsheets

More anomaly-free models of six-dimensional gauged supergravity

2d SCFTs from M2-branes

Comments on the twisted punctures of Aeven class S theory