Recursos de colección
Caltech Authors (167.915 recursos)
Repository of works by Caltech published authors.
Group = Walter Burke Institute for Theoretical Physics
Repository of works by Caltech published authors.
Group = Walter Burke Institute for Theoretical Physics
Argyres, Philip C.; Long, Cody; Martone, Mario
We compute the spectrum of scaling dimensions of Coulomb branch operators in 4d rank-2 N=2 superconformal field theories. Only a finite rational set of scaling dimensions is allowed. It is determined by using information about the global topology of the locus of metric singularities on the Coulomb branch, the special Kähler geometry near those singularities, and electric-magnetic duality monodromies along orbits of the U(1)_R symmetry. A set of novel topological and geometric results are developed which promise to be useful for the study and classification of Coulomb branch geometries at all ranks.
Dimofte, Tudor; Gaiotto, Davide; Paquette, Natalie M.
We propose matching pairs of half-BPS boundary conditions related by IR dualities of 3d N = 2 gauge theories. From these matching pairs we construct duality interfaces. We test our proposals by anomaly matching and the computation of supersymmetric indices. Examples include basic abelian dualities, level-rank dualities, and Aharony dualities.
Fuller, Jim; Ro, Stephen
Pre-supernova (SN) outbursts from massive stars may be driven by hydrodynamical wave energy emerging from the core of the progenitor star during late nuclear-burning phases. Here, we examine the effects of wave heating in stars containing little or no hydrogen, i.e. progenitors of Type IIb/Ib SNe. Because there is no massive hydrogen envelope, wave energy is thermalized near the stellar surface where the overlying atmospheric mass is small but the optical depth is large. Wave energy can thus unbind this material, driving an optically thick, super-Eddington wind. Using 1D hydrodynamic MESAsimulations of ∼5 M⊙ He stars, we find that wave heating...
Hossein Nouri, Fatemeh; Duez, Matthew D.; Foucart, Francois; Deaton, M. Brett; Haas, Roland; Haddadi, Milad; Kidder, Lawrence E.; Ott, Christian D.; Pfeiffer, Harald P.; Scheel, Mark A.; Szilagyi, Bela
Black hole–torus systems from compact binary mergers are possible engines for gamma-ray bursts (GRBs). During the early evolution of the postmerger remnant, the state of the torus is determined by a combination of neutrino cooling and magnetically driven heating processes, so realistic models must include both effects. In this paper, we study the postmerger evolution of a magnetized black hole–neutron star binary system using the Spectral Einstein Code (SpEC) from an initial postmerger state provided by previous numerical relativity simulations. We use a finite-temperature nuclear equation of state and incorporate neutrino effects in a leakage approximation. To achieve the needed...
Goldberger, Walter D.; Ridgway, Alexander K.
We extend the perturbative classical double copy to the analysis of bound systems. We first obtain the leading order perturbative gluon radiation field sourced by a system of interacting color charges in arbitrary time dependent orbits, and test its validity by taking relativistic bremsstrahlung and nonrelativistic bound state limits. By generalizing the color to kinematic replacement rules recently used in the context of classical bremsstrahlung, we map the gluon emission amplitude to the radiation fields of dilaton gravity sourced by interacting particles in generic (self-consistent) orbits. As an application, we reproduce the leading post-Newtonian radiation fields and energy flux for...
Peng, Yang; Refael, Gil
Combining physical and synthetic dimensions allows a controllable realization and manipulation of high-dimensional topological states. In our work, we introduce two quasiperiodically driven one-dimensional systems which enable tunable topological energy conversion between different driving sources. Using three drives, we realize a four-dimensional quantum Hall state which allows energy conversion between two of the drives within the bulk of the one-dimensional system. With only two drives, we achieve energy conversion between the two at the edge of the chain. Both effects are a manifestation of the effective axion electrodynamics in a three-dimensional time-reversal-invariant topological insulator. Furthermore, we explore the effects of...
Chen, Chien-Yi; Hill, Richard J.; Solon, Mikhail P.; Wijangco, Alexander M.
WIMP-nucleon scattering is analyzed at order 1/M in Heavy WIMP Effective Theory. The 1/M power corrections, where M ≫ m_W is the WIMP mass, distinguish between different underlying UV models with the same universal limit and their impact on direct detection rates can be enhanced relative to naive expectations due to generic amplitude-level cancellations at leading order. The necessary one- and two-loop matching calculations onto the low-energy effective theory for WIMP interactions with Standard Model quarks and gluons are performed for the case of an electroweak SU(2) triplet WIMP, considering both the cases of elementary fermions and composite scalars. The...
Ruby, Michael; Heinrich, Benjamin W.; Peng, Yang; von Oppen, Felix; Franke, Katharina J.
Magnetic adsorbates on superconductors induce local bound states within the superconducting gap. These Yu-Shiba-Rusinov (YSR) states decay slowly away from the impurity compared to atomic orbitals, even in 3D bulk crystals. Here, we use scanning tunneling spectroscopy to investigate their hybridization between two nearby magnetic Mn adatoms on a superconducting Pb(001) surface. We observe that the hybridization leads to the formation of symmetric and antisymmetric combinations of YSR states. We investigate how the structure of the dimer wave functions and the energy splitting depend on the shape of the underlying monomer orbitals and the orientation of the dimer with respect...
Yunger Halpern, Nicole; Swingle, Brian; Dressel, Justin
Two topics, evolving rapidly in separate fields, were combined recently: the out-of-time-ordered correlator (OTOC) signals quantum-information scrambling in many-body systems. The Kirkwood-Dirac (KD) quasiprobability represents operators in quantum optics. The OTOC was shown to equal a moment of a summed quasiprobability [Yunger Halpern, Phys. Rev. A 95, 012120 (2017)]. That quasiprobability, we argue, is an extension of the KD distribution. We explore the quasiprobability's structure from experimental, numerical, and theoretical perspectives. First, we simplify and analyze Yunger Halpern's weak-measurement and interference protocols for measuring the OTOC and its quasiprobability. We decrease, exponentially in system size, the number of trials required...
Chen, Baoyi; Stein, Leo C.
Black holes are a powerful setting for studying general relativity and theories beyond GR. However, analytical solutions for rotating black holes in beyond-GR theories are difficult to find because of the complexity of such theories. In this paper, we solve for the deformation to the near-horizon extremal Kerr metric due to two example string-inspired beyond-GR theories: Einstein-dilaton-Gauss-Bonnet and dynamical Chern-Simons theory. We accomplish this by making use of the enhanced symmetry group of NHEK and the weak-coupling limit of EdGB and dCS. We find that the EdGB metric deformation has a curvature singularity, while the dCS metric is regular. From...
Kapustin, Anton; McKinney, Tristan; Rothstein, Ira Z.
We study 2D fermions with a short-range interaction in the presence of a van
Hove singularity. It is shown that this system can be consistently described by
an effective field theory whose Fermi surface is subdivided into regions as
defined by a factorization scale, and that the theory is renormalizable in the
sense that all of the counterterms are well defined in the IR limit. The theory
has the unusual feature that the renormalization group equation for the
coupling has an explicit dependence on the renormalization scale, much as in
theories of Wilson lines. In contrast to the case of a round Fermi surface,
there are multiple marginal...
An, Haipeng; Pospelov, Maxim; Pradler, Josef; Ritz, Adam
If dark matter (DM) particles are lighter than a few MeV/c^2 and can scatter off electrons, their interaction within the solar interior results in a considerable hardening of the spectrum of galactic dark matter received on Earth. For a large range of the mass versus cross section parameter space, {m_e,σ_e}, the “reflected” component of the DM flux is far more energetic than the end point of the ambient galactic DM energy distribution, making it detectable with existing DM detectors sensitive to an energy deposition of 10−10^3 eV. After numerically simulating the small reflected component of the DM flux, we calculate...
Xie, Dan; Ye, Ke
We study S-duality of Argyres-Douglas theories obtained by compactification of 6d (2,0) theories of ADE type on a sphere with irregular punctures. The weakly coupled descriptions are given by the degeneration limit of auxiliary Riemann sphere with marked points, among which three punctured sphere represents isolated superconformal theories. We also discuss twisted irregular punctures and their S-duality.
Albert, Victor V.; Noh, Kyungjoo; Duivenvoorden, Kasper; Young, Dylan J.; Brierley, R. T.; Reinhold, Philip; Vuillot, Christophe; Li, Linshu; Shen, Chao; Girvin, S. M.; Terhal, Barbara M.; Jiang, Liang
The early Gottesman, Kitaev, and Preskill (GKP) proposal for encoding a qubit in an oscillator has recently been followed by cat- and binomial-code proposals. Numerically optimized codes have also been proposed, and we introduce codes of this type here. These codes have yet to be compared using the same error model; we provide such a comparison by determining the entanglement fidelity of all codes with respect to the bosonic pure-loss channel (i.e., photon loss) after the optimal recovery operation. We then compare achievable communication rates of the combined encoding-error-recovery channel by calculating the channel's hashing bound for each code. Cat...
Squire, J.; Hopkins, P. F.
We show that grains streaming through a fluid are generically unstable if their velocity, projected along some direction, matches the phase velocity of a fluid wave (linear oscillation). This can occur whenever grains stream faster than any fluid wave. The wave itself can be quite general—sound waves, magnetosonic waves, epicyclic oscillations, and Brunt–Väisälä oscillations each generate instabilities, for example. We derive a simple expression for the growth rates of these "resonant drag instabilities" (RDI). This expression (i) illustrates why such instabilities are so virulent and generic and (ii) allows for simple analytic computation of RDI growth rates and properties for...
Singh, Ashmeet; Carroll, Sean M.
We present a technique to coarse grain quantum states in a finite-dimensional Hilbert space. Our method is distinguished from other approaches by not relying on structures such as a preferred factorization of Hilbert space or a preferred set of operators (local or otherwise) in an associated algebra. Rather, we use the data corresponding to a given set of states, either specified independently or constructed from a single state evolving in time. Our technique is based on principle component analysis (PCA), and the resulting coarse-grained quantum states live in a lower-dimensional Hilbert space whose basis is defined using the underlying (isometric...
Wise, Mark B.; Zhang, Yue
We consider a fifth force to be an interaction that couples to matter with a
strength that grows with the number of atoms. In addition to competing with the
strength of gravity a fifth force can give rise to violations of the
equivalence principle. Current long range constraints on the strength and range
of fifth forces are very impressive. Amongst possible fifth forces are those
that couple to lepton flavorful charges $L_e-L_{\mu}$ or $L_e-L_{\tau}$. They
have the property that their range and strength are also constrained by
neutrino interactions with matter. In this brief note we review the existing
constraints on the allowed parameter space in gauged $U(1)_{L_e-L_{\mu},
L_{\tau}}$....
Iliesiu, Luca; Koloğlu, Murat; Mahajan, Raghu; Perlmutter, Eric; Simmons-Duffin, David
We initiate an approach to constraining conformal field theory (CFT) data at
finite temperature using methods inspired by the conformal bootstrap for vacuum
correlation functions. We focus on thermal one- and two-point functions of
local operators on the plane. The KMS condition for thermal two-point functions
is cast as a crossing equation. By studying the analyticity properties of
thermal two-point functions, we derive a "thermal inversion formula" whose
output is the set of thermal one-point functions for all operators appearing in
a given OPE. This involves identifying a kinematic regime which is the analog
of the Regge regime for four-point functions. We demonstrate the effectiveness
of the inversion formula...
Carroll, Sean M.
It seems natural to ask why the universe exists at all. Modern physics
suggests that the universe can exist all by itself as a self-contained system,
without anything external to create or sustain it. But there might not be an
absolute answer to why it exists. I argue that any attempt to account for the
existence of something rather than nothing must ultimately bottom out in a set
of brute facts; the universe simply is, without ultimate cause or explanation.
Pollack, Jason; Singh, Ashmeet
Field theories place one or more degrees of freedom at every point in space.
Hilbert spaces describing quantum field theories, or their finite-dimensional
discretizations on lattices, therefore have large amounts of structure: they
are isomorphic to the tensor product of a smaller Hilbert space for each
lattice site or point in space. Local field theories respecting this structure
have interactions which preferentially couple nearby points. The emergence of
classicality through decoherence relies on this framework of tensor-product
decomposition and local interactions. We explore the emergence of such lattice
structure from Hilbert-space considerations alone. We point out that the vast
majority of finite-dimensional Hilbert spaces cannot be isomorphic to the
tensor...