High Energy Physics - Theory

Authors and titles for September 2014

[401] arXiv:1409.4770 (cross-list from cond-mat.quant-gas) [pdf, other]

Title: Quantum simulation of non-trivial topology

Octavi Boada, Alessio Celi, Maciej Lewenstein, Javier Rodríguez-Laguna, José I. Latorre

Comments: 12 pages, 15 figures

Journal-ref: New Journal of Physics 17, 045007 (2015)

Subjects: Quantum Gases (cond-mat.quant-gas); Statistical Mechanics (cond-mat.stat-mech); High Energy Physics - Theory (hep-th); Quantum Physics (quant-ph)

[402] arXiv:1409.4777 (cross-list from astro-ph.CO) [pdf, other]

Title: CMB Anisotropies from a Gradient Mode

Mehrdad Mirbabayi, Matias Zaldarriaga

Comments: 21+8 pages. improved presentation

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[403] arXiv:1409.4916 (cross-list from cond-mat.str-el) [pdf, other]

Title: Topologically distinct critical theories emerging from the bulk entanglement spectrum of integer quantum Hall states on a lattice

Qiong Zhu, Xin Wan, Guang-Ming Zhang

Comments: 5 pages, 4 figures, published version

Journal-ref: Phys. Rev. B 90, 235134 (2014)

Subjects: Strongly Correlated Electrons (cond-mat.str-el); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); High Energy Physics - Theory (hep-th)

[404] arXiv:1409.4954 (cross-list from hep-ph) [pdf, other]

Title: Composite Z'

Michio Hashimoto

Comments: 6 pages, 4 figures; version published in PRD

Journal-ref: Phys. Rev. D 90, 096004 (2014)

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[405] arXiv:1409.4981 (cross-list from hep-ph) [pdf, other]

Title: Spin-charge-family theory is offering next step in understanding elementary particles and fields and correspondingly universe

Norma Susana Mankoc Borstnik

Comments: 42 pages, IOP Proceedings style, Proceedings to the Conference on Cosmology, Gravitational Waves and Particles, IARD conferences, Ljubljana, 6-9 June 2016, The 10^th Biennial Conference on Classical and Quantum Relativistic Dynamics of Particles and Fields,Appeared in proceedings of this conference. arXiv admin note: text overlap with arXiv:1312.1542

Journal-ref: J. Phys.: Conf. Ser. 845 (2017) 012017

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[406] arXiv:1409.5069 (cross-list from gr-qc) [pdf, other]

Title: Connecting horizon pixels and interior voxels of a black hole

Piero Nicolini, Douglas Singleton

Comments: 10 pages, 0 figures, published version with note added

Journal-ref: Phys.Lett. B738 (2014) 213-217

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[407] arXiv:1409.5078 (cross-list from hep-ph) [pdf, other]

Title: Inflationary cosmology and the standard model Higgs with a small Hubble induced mass

Kohei Kamada

Comments: 25 pages, 5 figures; v2: typos corrected, references, figures, and extended discussions added, matches version published in PLB

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

[408] arXiv:1409.5101 (cross-list from quant-ph) [pdf, other]

Title: Arbitrary Spin Galilean Oscillator

C. R. Hagen

Comments: 9 pages

Subjects: Quantum Physics (quant-ph); High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph)

[409] arXiv:1409.5119 (cross-list from gr-qc) [pdf, other]

Title: Temperature in warm inflation in non minimal kinetic coupling model

H. Mohseni Sadjadi, Parviz Goodarzi

Comments: 18 pages, major revision, accepted by the European Physical Journal C

Journal-ref: Eur. Phys. J. C (2015) 75: 513

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[410] arXiv:1409.5210 (cross-list from hep-lat) [pdf, other]

Title: Anderson localization in QCD-like theories

Matteo Giordano, Tamas G. Kovacs (Debrecen, Inst. Nucl. Res.), Ferenc Pittler (Eotvos U.)

Comments: to appear in special issue "Recent Nonperturbative Developments in QCD-like theories" of Int. J. Mod. Phys. A

Subjects: High Energy Physics - Lattice (hep-lat); Disordered Systems and Neural Networks (cond-mat.dis-nn); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[411] arXiv:1409.5255 (cross-list from quant-ph) [pdf, other]

Title: Semi-Classical Localisation Properties of Quantum Oscillators on a Noncommutative Configuration Space

Fabio Benatti, Laure Gouba

Comments: 12 pages

Journal-ref: Open Systems & Information Dynamics, Vol. 22, No 3 (2015) 1550001

Subjects: Quantum Physics (quant-ph); High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph)

[412] arXiv:1409.5277 (cross-list from math-ph) [pdf, other]

Title: On the Inverse Scattering Method for Integrable PDEs on a Star Graph

Vincent Caudrelier

Comments: 26 pages, final version. v2: Summary of results in introduction, new section 4.3 to improve the discussion on the global relation, complete discussion of the example in Section 5.1.1. v3: titles of references added

Journal-ref: Comm. Math. Phys. 338 (2015), 893

Subjects: Mathematical Physics (math-ph); High Energy Physics - Theory (hep-th); Analysis of PDEs (math.AP); Pattern Formation and Solitons (nlin.PS); Exactly Solvable and Integrable Systems (nlin.SI)

[413] arXiv:1409.5303 (cross-list from cond-mat.stat-mech) [pdf, other]

Title: On the complete-spectrum characterization of quantum integrable spin chains via the inhomogeneous T-Q relation

Junpeng Cao, Wen-Li Yang, Kangjie Shi, Yupeng Wang

Comments: 11 pages, no figure, new version

Journal-ref: J. Phys. A: Math. Theor. 48 (2015) 444001

Subjects: Statistical Mechanics (cond-mat.stat-mech); High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph)

[414] arXiv:1409.5412 (cross-list from hep-ph) [pdf, other]

Title: Non-Hermitian ${\cal PT}$-Symmetric Dirac-Pauli Hamiltonians with Real Energy Eigenvalues in the Magnetic Field

V.N. Rodionov

Comments: 19 pages, 5 figures, PHHQP2014. arXiv admin note: substantial text overlap with arXiv:1406.0383, arXiv:1404.0503

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph); Quantum Physics (quant-ph)

[415] arXiv:1409.5454 (cross-list from astro-ph.CO) [pdf, other]

Title: Simulating (p)reheating after inflation via the DCE?

Wade Naylor (Osaka U.)

Comments: 12 pages, 3 figures, submitted to special issue on "Casimir Physics" in Journal of Physics: Condensed Matter

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); Quantum Physics (quant-ph)

[416] arXiv:1409.5488 (cross-list from hep-ph) [pdf, other]

Title: Connecting the Hadron Mass Scale to the Fundamental Mass Scale of Quantum Chromodynamics

Alexandre Deur, Stanley J. Brodsky, Guy F. de Teramond

Comments: 11 pages, 4 figures. Final version published in Phys. Lett. B

Journal-ref: Phys. Lett. B 750, 528 (2015)

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Lattice (hep-lat); High Energy Physics - Theory (hep-th)

[417] arXiv:1409.5539 (cross-list from gr-qc) [pdf, other]

Title: Uninformed Hawking Radiation

I. Sakalli, A. Ovgun

Comments: 4 pages, minor corrections, corrected typos

Journal-ref: EPL 110 10008 (2015)

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[418] arXiv:1409.5548 (cross-list from gr-qc) [pdf, other]

Title: Thermodynamic phase transition based on the non-singular temperature

Myungseok Eune, Yongwan Gim, Wontae Kim

Comments: 12 pages, 5 figures, version to appear in PRD

Journal-ref: Phys. Rev. D 91, 044037 (2015)

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[419] arXiv:1409.5578 (cross-list from math-ph) [pdf, other]

Title: Construction of Quasi-solvable Quantum Mechanical Matrix Models: Lie Superalgebra v.s. N-fold Supersymmetry

Toshiaki Tanaka

Comments: 28 pages, no figures

Subjects: Mathematical Physics (math-ph); High Energy Physics - Theory (hep-th); Exactly Solvable and Integrable Systems (nlin.SI)

[420] arXiv:1409.5621 (cross-list from math-ph) [pdf, other]

Title: A Givental-like Formula and Bilinear Identities for Tensor Models

Stephane Dartois

Comments: 18 pages, 1 figure

Subjects: Mathematical Physics (math-ph); High Energy Physics - Theory (hep-th)

[421] arXiv:1409.5695 (cross-list from gr-qc) [pdf, other]

Title: On a symmetry relating gravity with antigravity

Israel Quiros

Comments: 9 pages, no figures. This is a sequel to the earlier paper arXiv:gr-qc/0411064. A section on the normalized gravitational charge added. Physical discussion enriched

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[422] arXiv:1409.5723 (cross-list from math.QA) [pdf, other]

Title: Boundary Conditions for Topological Quantum Field Theories, Anomalies and Projective Modular Functors

Domenico Fiorenza, Alessandro Valentino

Comments: 26 pages, 6 figures. Exposition improved, bibliography updated. Final version, to appear in Comm. Math. Phys

Subjects: Quantum Algebra (math.QA); High Energy Physics - Theory (hep-th); Category Theory (math.CT)

[423] arXiv:1409.5751 (cross-list from math-ph) [pdf, other]

Title: An analysis of the intermediate field theory of $T^4$ tensor model

Viet Anh Nguyen, Stephane Dartois, Bertrand Eynard

Comments: 16 pages, 2 figures

Subjects: Mathematical Physics (math-ph); High Energy Physics - Theory (hep-th)

[424] arXiv:1409.5787 (cross-list from quant-ph) [pdf, other]

Title: Scattering solutions of the Klein Gordon equation for a step potential with hyperbolic tangent potential

Clara Rojas

Comments: 8 pages, 5 figures

Journal-ref: Modern Physics Letters A. Vol. 29, No. 28 (2014), 1450146

Subjects: Quantum Physics (quant-ph); High Energy Physics - Theory (hep-th)

[425] arXiv:1409.5799 (cross-list from hep-ph) [pdf, other]

Title: Universal Constraints on Axions from Inflation

Ricardo Z. Ferreira, Martin S. Sloth

Comments: 22 pages, 1 figure; V3: Published version

Journal-ref: JHEP 12 (2014) 139

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

[426] arXiv:1409.5800 (cross-list from gr-qc) [pdf, other]

Title: The Quasinormal Modes of Weakly Charged Kerr-Newman Spacetimes

Zachary Mark, Huan Yang, Aaron Zimmerman, Yanbei Chen

Comments: 4+3 pages, 2 figures, data (along with a read-me file) provided for eight modes

Journal-ref: Phys. Rev. D 91, 044025 (2015)

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)

[427] arXiv:1409.5823 (cross-list from gr-qc) [pdf, other]

Title: General Relativity and Gravitation: A Centennial Perspective

Abhay Ashtekar, Beverly K. Berger, James Isenberg, Malcolm A. H. MacCallum

Comments: 37 pages

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph)

[428] arXiv:1409.5946 (cross-list from quant-ph) [pdf, other]

Title: Entanglement area law from specific heat capacity

Fernando G.S.L. Brandao, Marcus Cramer

Comments: v3 now featuring bosonic systems

Journal-ref: Phys. Rev. B 92, 115134 (2015)

Subjects: Quantum Physics (quant-ph); Statistical Mechanics (cond-mat.stat-mech); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph)

[429] arXiv:1409.5979 (cross-list from hep-ph) [pdf, other]

Title: Dynamical mass generation in unquenched QED using the Dyson--Schwinger equations

Ayse Kizilersu, Michael R. Pennington, Tom Sizer, Anthony G. Williams, Richard Williams

Comments: 17 pages, 13 figures, 3 tables

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[430] arXiv:1409.5996 (cross-list from math.AG) [pdf, other]

Title: Bogomolov-Tian-Todorov theorems for Landau-Ginzburg models

Ludmil Katzarkov, Maxim Kontsevich, Tony Pantev

Comments: LaTeX, 74 pages, new corrected title, missing references restored, typos fixed, new references added

Subjects: Algebraic Geometry (math.AG); High Energy Physics - Theory (hep-th); Category Theory (math.CT); Symplectic Geometry (math.SG)

[431] arXiv:1409.6044 (cross-list from gr-qc) [pdf, other]

Title: Particle production from marginally trapped surfaces of general spacetimes

José M. M. Senovilla, Ramón Torres

Comments: 24 pages, 2 figures. Section 4.2, concerning the analysis of the Kerr-Vaidya solution, has been rewritten, correcting mistakes in previous versions. The corrected calculations do support our claims. A corrigendum has also been sent to CQG. New references added. Some of the mistakes in previous versions are actually common and spread in the literature on the Kerr-Vaidya solution

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[432] arXiv:1409.6078 (cross-list from astro-ph.CO) [pdf, other]

Title: Revisiting the holographic dark energy in a non-flat universe: alternative model and cosmological parameter constraints

Jing-Fei Zhang, Ming-Ming Zhao, Jing-Lei Cui, Xin Zhang

Comments: 8 pages, 4 figures

Journal-ref: Eur. Phys. J. C 74 (2014) 3178

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[433] arXiv:1409.6114 (cross-list from hep-ph) [pdf, other]

Title: Two-loop Master Integrals with the Simplified Differential Equations approach

Costas G. Papadopoulos, Damiano Tommasini, Christopher Wever

Comments: 4 figures, 6 ancillary files. Version as published in JHEP

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[434] arXiv:1409.6119 (cross-list from astro-ph.CO) [pdf, other]

Title: An accurate determination of the Hubble constant from Baryon Acoustic Oscillation datasets

Cheng Cheng, Qing-Guo Huang

Comments: 13 pages, 5 figures, 2 tables

Journal-ref: Sci China-Phys Mech Astron, 58 (2015) 599801

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[435] arXiv:1409.6137 (cross-list from hep-ph) [pdf, other]

Title: Polarized triple-collinear splitting functions at NLO for processes with photons

German F. R. Sborlini, Daniel de Florian, German Rodrigo

Comments: 31 pages, no figures. Exact results for photon started-processes available in Appendix A. Improved discussion about implementation and typos corrected. Final version published in JHEP

Journal-ref: JHEP 03 (2015) 021

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[436] arXiv:1409.6218 (cross-list from astro-ph.CO) [pdf, other]

Title: Polymer inflation

Syed Moeez Hassan, Viqar Husain, Sanjeev S. Seahra

Comments: 14 pages, 6 figures. In addition to minor changes and added references, we have included a new discussion and figure (#5) concerning the possibility of sub-Planckian initial data inducing significant slow roll inflation. Matches the version in press in PRD

Journal-ref: Phys. Rev. D 91, 065006 (2015)

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[437] arXiv:1409.6232 (cross-list from gr-qc) [pdf, other]

Title: Towards obtaining Green functions for a Casimir cavity in de Sitter spacetime

Giampiero Esposito, George M. Napolitano

Comments: 13 pages, special issue review article. In the final version, the calculations of Sec. III have been improved, two References have been added and their content has been summarized

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[438] arXiv:1409.6331 (cross-list from math.QA) [pdf, other]

Title: Nonassociative geometry in quasi-Hopf representation categories I: Bimodules and their internal homomorphisms

Gwendolyn E. Barnes, Alexander Schenkel, Richard J. Szabo

Comments: v1: 56 pages. v2: 57 pages. Introduction expanded. Published in Journal of Geometry and Physics

Journal-ref: Journal of Geometry and Physics, Volume 89, March 2015, Pages 111-152

Subjects: Quantum Algebra (math.QA); High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph)

[439] arXiv:1409.6342 (cross-list from quant-ph) [pdf, other]

Title: Scattering of a scalar relativistic particle by the hyperbolic tangent potential

Clara Rojas

Comments: 6 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1409.5787

Journal-ref: Canadian Journal of Physics, 10.1139/cjp-2014-0309

Subjects: Quantum Physics (quant-ph); High Energy Physics - Theory (hep-th)

[440] arXiv:1409.6395 (cross-list from nucl-th) [pdf, other]

Title: Chiral electric separation effect in the quark-gluon plasma

Yin Jiang, Xu-Guang Huang, Jinfeng Liao

Comments: V1: 14 pages,3 figures. V2: Typos corrected and two new appendices added. Matches published version

Journal-ref: Phys. Rev. D 91, 045001 (2015)

Subjects: Nuclear Theory (nucl-th); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[441] arXiv:1409.6406 (cross-list from gr-qc) [pdf, other]

Title: Electric-magnetic duality and renormalization in curved spacetimes

Ivan Agullo, Aitor Landete, Jose Navarro-Salas

Comments: 7 pages, 0 figures, Published version

Journal-ref: Phys.Rev. D90 (2014) 12, 124067

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[442] arXiv:1409.6539 (cross-list from hep-ph) [pdf, other]

Title: Matrix Models for Deconfinement and Their Perturbative Corrections

Yun Guo

Comments: 29 pages, 1 table, 5 figs, final version to appear in JHEP

Journal-ref: JHEP 1411 (2014) 111

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); Nuclear Theory (nucl-th)

[443] arXiv:1409.6558 (cross-list from cond-mat.str-el) [pdf, other]

Title: Quantum quench in long-range field theories

M. A. Rajabpour, S. Sotiriadis

Comments: 14 pages, 8 figures, V2: published version

Journal-ref: Phys. Rev. B 91, 045131 (2015)

Subjects: Strongly Correlated Electrons (cond-mat.str-el); Statistical Mechanics (cond-mat.stat-mech); High Energy Physics - Theory (hep-th)

[444] arXiv:1409.6562 (cross-list from astro-ph.CO) [pdf, other]

Title: Diagnosing holographic dark energy models with statefinder hierarchy

Jing-Fei Zhang, Jing-Lei Cui, Xin Zhang

Comments: 9 pages, 8 figures; published version

Journal-ref: Eur. Phys. J. C 74 (2014) 3100

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[445] arXiv:1409.6568 (cross-list from astro-ph.CO) [pdf, other]

Title: Generalised tensor fluctuations and inflation

Dario Cannone, Gianmassimo Tasinato, David Wands

Comments: 20 pages. V3: typos corrected and references added. Matches version published in JCAP

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[446] arXiv:1409.6656 (cross-list from gr-qc) [pdf, other]

Title: Local Well-posedness of Lovelock gravity

Steven Willison

Comments: 2 pages, no figures. This article agrees with the published version apart from small corrections in equation 2 and text below equations 2 and 7

Journal-ref: Class. Quant. Grav. 32 022001 (2015)

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th); Analysis of PDEs (math.AP)

[447] arXiv:1409.6660 (cross-list from cond-mat.stat-mech) [pdf, other]

Title: Non-equilibrium steady states in the Klein-Gordon theory

Benjamin Doyon, Andrew Lucas, Koenraad Schalm, M. J. Bhaseen

Comments: 42 pages, 7 figures

Journal-ref: J. Phys. A: Math. Theor. 48 (2015) 095002

Subjects: Statistical Mechanics (cond-mat.stat-mech); High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph)

[448] arXiv:1409.6695 (cross-list from math-ph) [pdf, other]

Title: Minimal Realizations of Supersymmetry for Matrix Hamiltonians

Alexander A. Andrianov, Andrey V. Sokolov

Comments: 9 pages

Journal-ref: Physics Letters A 379:4 (2015) pp. 279-283

Subjects: Mathematical Physics (math-ph); High Energy Physics - Theory (hep-th); Quantum Physics (quant-ph)

[449] arXiv:1409.6708 (cross-list from gr-qc) [pdf, other]

Title: Hamiltonian analysis of spatially covariant gravity

Xian Gao

Comments: v1: 17 pages; v2: 15 pages, double column, this http URL extended, comments added, typos corrected

Journal-ref: Phys. Rev. D 90, 104033 (2014)

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[450] arXiv:1409.6867 (cross-list from gr-qc) [pdf, other]

Title: Electromagnetism with dimension-five operators

Leonardo Campanelli

Comments: 7 pages, no figures, typos corrected, version matching the published one in Physical Review D

Journal-ref: Phys. Rev. D 90, 105014 (2014)

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)