140 research outputs found
Integrable achiral D5-brane reflections and asymptotic Bethe equations
We study the reflection of magnons from a D5-brane in the framework of the
AdS/CFT correspondence. We consider two possible orientations of the D5-brane
with respect to the reference vacuum state, namely vacuum states aligned along
"vertical" and "horizontal" directions. We show that the reflections are of the
achiral type. We also show that the reflection matrices satisfy the boundary
Yang-Baxter equations for both orientations. In the horizontal case the
reflection matrix can be interpreted in terms of a bulk S-matrix, S(p, -p), and
factorizability of boundary scattering therefore follows from that of bulk
scattering. Finally, we solve the nested coordinate Bethe ansatz for the system
in the vertical case to find the Bethe equations. In the horizontal case, the
Bethe equations are of the same form as those for the closed string.Comment: 27 pages, 4 figures, v2: published versio
Coideal Quantum Affine Algebra and Boundary Scattering of the Deformed Hubbard Chain
We consider boundary scattering for a semi-infinite one-dimensional deformed
Hubbard chain with boundary conditions of the same type as for the Y=0 giant
graviton in the AdS/CFT correspondence. We show that the recently constructed
quantum affine algebra of the deformed Hubbard chain has a coideal subalgebra
which is consistent with the reflection (boundary Yang-Baxter) equation. We
derive the corresponding reflection matrix and furthermore show that the
aforementioned algebra in the rational limit specializes to the (generalized)
twisted Yangian of the Y=0 giant graviton.Comment: 21 page. v2: minor correction
The Bound State S-matrix of the Deformed Hubbard Chain
In this work we use the q-oscillator formalism to construct the atypical
(short) supersymmetric representations of the centrally extended Uq (su(2|2))
algebra. We then determine the S-matrix describing the scattering of arbitrary
bound states. The crucial ingredient in this derivation is the affine extension
of the aforementioned algebra.Comment: 44 pages, 3 figures. v2: minor correction
On the reflection of magnon bound states
We investigate the reflection of two-particle bound states of a free open
string in the light-cone AdS_5 x S^5 string sigma model, for large angular
momentum J=J_56 and ending on a D7 brane which wraps the entire AdS_5 and a
maximal S^3 of S^5. We use the superspace formalism to analyse fundamental and
two-particle bound states in the cases of supersymmetry-preserving and
broken-supersymmetry boundaries. We find the boundary S-matrices corresponding
to bound states both in the bulk and on the boundary.Comment: 35 pages, v2: few typos and ref corrected, accepted for publication
in JHE
SecureCore software architecture: Trusted Management Layer (TML) Kernel Extension Module Integration Guide
A mobile computing device has more inherent risk than desktops or most other stationary computing devices. Such mobile devices are typically carried outside of a controlled physical environment, and they must communicate over an insecure medium. The risk is even greater if the data being stored, processed and transmitted by the mobile device is classified. The purpose of the SecureCore research project is to investigate fundamental architectural features required for the trusted operation of mobile computing devices so the security is built-in, transparent and flexible. A building block for the SecureCore project is a Least Privilege Separation Kernel (LPSK). The LPSK together with extension modules provides the security base. Integration of extension modules with the LPSK is described, including coding techniques, and compile and link directions.Funding number: CNS-0430566.Approved for public release; distribution is unlimited
Twisted Yangians for symmetric pairs of types B, C, D
We study a class of quantized enveloping algebras, called twisted Yangians, associated with the symmetric pairs of types B, C, D in Cartan's classification. These algebras can be regarded as coideal subalgebras of the extended Yangian for orthogonal or symplectic Lie algebras. They can also be presented as quotients of a reflection algebra by additional symmetry relations. We prove an analogue of the Poincare-Birkoff-Witt Theorem, determine their centres and study also extended reflection algebras
Secret Symmetries in AdS/CFT
We discuss special quantum group (secret) symmetries of the integrable system
associated to the AdS/CFT correspondence. These symmetries have by now been
observed in a variety of forms, including the spectral problem, the boundary
scattering problem, n-point amplitudes, the pure-spinor formulation and quantum
affine deformations.Comment: 20 pages, pdfLaTeX; Submitted to the Proceedings of the Nordita
program `Exact Results in Gauge-String Dualities'; Based on the talk
presented by A.T., Nordita, 15 February 201
Representations of twisted Yangians of types B, C, D: I
We initiate a theory of highest weight representations for twisted Yangians of types B, C, D and we classify the finite-dimensional irreducible representations of twisted Yangians associated to symmetric pairs of types CI, DIII and BCD0
Does VO2 Host a Transient Monoclinic Metallic Phase?
Ultrafast phase transitions induced by femtosecond light pulses present a new
opportunity for manipulating the properties of materials. Understanding how
these transient states are different from, or similar to, their thermal
counterparts is key to determining how materials can exhibit properties that
are not found in equilibrium. In this paper, we reexamine the case of the
light-induced insulator-metal phase transition in the prototypical, strongly
correlated material VO, for which a nonthermal Mott-Hubbard transition has
been claimed. Here, we show that heat, even on the ultrafast timescale, plays a
key role in the phase transition. When heating is properly accounted for, we
find a single phase-transition threshold corresponding to the thermodynamic
structural insulator-metal phase transition, and we find no evidence of a
hidden transient Mott-Hubbard nonthermal phase. The interplay between the
initial thermal state and the ultrafast transition may have implications for
other transient states of matter
The Anthropocene is functionally and stratigraphically distinct from the Holocene
Human activity is leaving a pervasive and persistent signature on Earth. Vigorous debate continues about whether this warrants recognition as a new geologic time unit known as the Anthropocene. We review anthropogenic markers of functional changes in the Earth system through the stratigraphic record. The appearance of manufactured materials in sediments − including aluminum, plastics and concrete − coincides with global spikes in fallout radionuclides and particulates from fossil-fuel combustion. Carbon, nitrogen, and phosphorus cycles have been substantially modified over the last century. Rates of sea-level rise, and the extent of human perturbation of the climate system, exceed Late Holocene changes. Biotic changes include species invasions worldwide and accelerating rates of extinction. These combined signals render the Anthropocene stratigraphically distinct from the Holocene and earlier epochs
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