Since superstring theories are necessarily ten-dimensional theories, any discussion of phenomenology must begin with a discussion of how apparent four-dimensional physics is related to underlying ten-dimensional physics. The present chapter is devoted to this question. We will carry out the discussion in the context of field theory, but with an emphasis on properties that depend only on qualitative assumptions, not numerical details, and so can remain valid in string theory. What we will try to accomplish in this chapter is not to develop detailed models of compactification but to set the stage and introduce some of the essential concepts.
The GUT-based approach to physics has been attractive since it was first put forward close to thirty years ago; it has been enriched by new ideas, notably supersymmetry and strings; and there are real hints that it is on the right track, notably from measurements of the weak mixing angle and neutrino masses. In this article (based on my Heinrich Hertz lecture at SUSY 2002 at DESY, June, 2002), some of the arguments for grand unification will be reviewed.
We develop an approach to Khovanov homology of knots via gauge theory (previous physics-based approaches involved other descriptions of the relevant spaces of BPS states). The starting point is a system of D3-branes ending on an NS5-brane with a nonzero theta-angle. On the one hand, this system can be related to a Chern–Simons gauge theory on the boundary of the D3-brane worldvolume; on the other hand, it can be studied by standard techniques of S-duality and T-duality. Combining the two approaches leads to a new and manifestly invariant description of the Jones polynomial of knots, and its generalizations, and to a manifestly invariant description of Khovanov homology, in terms of certain elliptic partial differential equations in four and five dimensions.
Mössbauer spectroscopy and dc magnetization measurements have been used to characterize the low temperature magnetism of a rigorously linear, two-coordinate complex of high-spin Fe(II), Fe[(C(Si(CH3)3]2 (1). The local C-Fe-C chromophore of 1 exhibits novel slow, single-ion paramagnetic relaxation and fully resolved magnetic hyperfine splitting of its zero field Mössbauer spectrum over the range approximately 100 to approximately 50K. The hyperfine field at 4.2 K is 152 T! This is the largest magnetic hyperfine field observed for iron to date regardless of spin, oxidation state, or coordination environment. This observation is attributable to the large unquenched orbital angular momentum corresponding to the degenerate ground (dxy, dx2-y2) orbital pair of 1 in local Dinfinityh symmetry. Maintenance of the ground-state degeneracy is required by the Jahn-Teller theorem leading to the unprecedented result that the magnitude of the magnetic moment of 1's 5Deltag ground state is essentially that of the parent free ion (5D4) ground term.
This paper is devoted to a systematic discussion of the supersymmetric index Tr (-1)^ for the minimal supersymmetric Yang-Mills theory -with any simple gauge group G -primarily in four spacetime dimensions.The index has refinements that probe confinement and oblique confinement and the possible spontaneous breaking of chiral symmetry and of global symmetries, such as charge conjugation, that are derived from outer automorphisms of the gauge group.Predictions for the index and its refinements are obtained on the basis of standard hypotheses about the infrared behavior of gauge theories.The predictions are confirmed via microscopic calculations which involve a Born-Oppenheimer computation of the spectrum as well as mathematical formulas involving triples of commuting elements of G and the Chern-Simons invariants of flat bundles on the three-torus.
Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Edward Witten; Flavor Prospects. AIP Conf. Proc. 14 September 2004; 722 (1): 251–254. https://doi.org/10.1063/1.1807329 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search
These notes aim to provide an introduction to the basics of black hole thermodynamics. After explaining Bekenstein's original proposal that black holes have entropy, we discuss Hawking's discovery of black hole radiation, its analog for Rindler space in the Unruh effect, the Euclidean approach to black hole thermodynamics, some basics about von Neumann entropy and its applications, the Ryu-Takayanagi formula, and the nature of a white hole.
Some properties of the anomaly-free O(32) superstring theory recently discovered by Green and Schwarz are discussed. With proper choice of ground state, the theory leads in four dimensions to an SU(5) theory with any desired number of standard generations (and no exotic or mirror fermions). It predicts axions and stable Nielsen–Olesen vortex lines. It can be consistently compactified only if certain topological conditions are imposed.
No abstract is provided for this article.
Making use of known facts about 'tensor models', it is possible to construct a quantum system without quenched disorder that has the same large n limit for its correlation functions and thermodynamics as the SYK model. This might be useful in further probes of this approach to holographic duality.
Recently Leutheusser and Liu [1,2] identified an emergent algebra of Type III$_1$ in the operator algebra of ${\mathcal N}=4$ super Yang-Mills theory for large $N$. Here we describe some $1/N$ corrections to this picture and show that the emergent Type III$_1$ algebra becomes an algebra of Type II$_\infty$. The Type II$_\infty$ algebra is the crossed product of the Type III$_1$ algebra by its modular automorphism group. In the context of the emergent Type II$_\infty$ algebra, the entropy of a black hole state is well-defined up to an additive constant, independent of the state. This is somewhat analogous to entropy in classical physics.
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This paper summarizes our rather lengthy paper, “Algebra of the Infrared: String Field Theoretic Structures in Massive 𝒩=(2,2) Field Theory In Two Dimensions,” and is meant to be an informal, yet detailed, introduction and summary of that larger work.
Modern Classical Physics: Optics, Fluids, Plasmas, Elasticity, Relativity, and Statistical Physics, Kip S. Thorne and Roger D. Blandford, Princeton U. Press, 2017, $125.00 Buy at Amazon
We develop an approach to Khovanov homology of knots via gauge theory (previous physics-based approches involved other descriptions of the relevant spaces of BPS states). The starting point is a system of D3-branes ending on an NS5-brane with a nonzero theta-angle. On the one hand, this system can be related to a Chern-Simons gauge theory on the boundary of the D3-brane worldvolume; on the other hand, it can be studied by standard techniques of $S$-duality and $T$-duality. Combining the two approaches leads to a new and manifestly invariant description of the Jones polynomial of knots, and its generalizations, and to a manifestly invariant description of Khovanov homology, in terms of certain elliptic partial differential equations in four and five dimensions.
We analyze the algebra of boundary observables in canonically quantised JT gravity with or without matter. In the absence of matter, this algebra is commutative, generated by the ADM Hamiltonian. After coupling to a bulk quantum field theory, it becomes a highly noncommutative algebra of Type II$_\infty$ with a trivial center. As a result, density matrices and entropies on the boundary algebra are uniquely defined up to, respectively, a rescaling or shift. We show that this algebraic definition of entropy agrees with the usual replica trick definition computed using Euclidean path integrals. Unlike in previous arguments that focused on $\mathcal{O}(1)$ fluctuations to a black hole of specified mass, this Type II$_\infty$ algebra describes states at all temperatures or energies. We also consider the role of spacetime wormholes. One can try to define operators associated with wormholes that commute with the boundary algebra, but this fails in an instructive way. In a regulated version of the theory, wormholes and topology change can be incorporated perturbatively. The bulk Hilbert space $\mathcal{H}_\mathrm{bulk}$ that includes baby universe states is then much bigger than the space of states $\mathcal{H}_\mathrm{bdry}$ accessible to a boundary observer. However, to a boundary observer, every pure or mixed state on $\mathcal{H}_\mathrm{bulk}$ is equivalent to some pure state in $\mathcal{H}_\mathrm{bdry}$.
