Hasil untuk "hep-th"

Menampilkan 20 dari ~668233 hasil · dari DOAJ, arXiv, Semantic Scholar

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arXiv Open Access 2025
FeynTune: Large Language Models for High-Energy Theory

Paul Richmond, Prarit Agarwal, Borun Chowdhury et al.

We present specialized Large Language Models for theoretical High-Energy Physics, obtained as 20 fine-tuned variants of the 8-billion parameter Llama-3.1 model. Each variant was trained on arXiv abstracts (through August 2024) from different combinations of hep-th, hep-ph and gr-qc. For a comparative study, we also trained models on datasets that contained abstracts from disparate fields such as the q-bio and cs categories. All models were fine-tuned using two distinct Low-Rank Adaptation fine-tuning approaches and varying dataset sizes, and outperformed the base model on hep-th abstract completion tasks. We compare performance against leading commercial LLMs (ChatGPT, Claude, Gemini, DeepSeek) and derive insights for further developing specialized language models for High-Energy Theoretical Physics.

en cs.CL, cs.LG
arXiv Open Access 2011
Note About Hamiltonian Structure of Non-Linear Massive Gravity

J. Kluson

We perform the Hamiltonian analysis of non-linear massive gravity action studied recently in arXiv:1106.3344 [hep-th]. We show that the Hamiltonian constraint is the second class constraint. As a result the theory possesses an odd number of the second class constraints and hence all non physical degrees of freedom cannot be eliminated.

en hep-th, gr-qc
arXiv Open Access 2009
SUSY Gauge Singlets and Dualities

James Barnard

We discuss how, by including gauge singlets in supersymmetric gauge theories, one can construct and test new types of duality. This may help in finding dual theories of supersymmetric GUTs. This talk is based on the recent article arXiv:0903.1313 [hep-th].

en hep-th
arXiv Open Access 2009
Transformations of triangle ladder diagrams

Igor Kondrashuk, Alvaro Vergara

It is shown how dual space diagrammatic representation of momentum integrals corresponding to triangle ladder diagrams with an arbitrary number of rungs can be transformed to half-diamonds. In paper arXiv:0803.3420 [hep-th] the half-diamonds were related by conformal integral substitution to the diamonds which represent the dual space image of four-point ladder integrals in the four-dimensional momentum space. Acting in the way described in the present paper we do not need to use the known result for diamond (four-point) diagrams as an external input in deriving relations of arXiv:0803.3420 [hep-th], however, that result for the diamond diagram arises in the present proof as an intermediate consequence in a step-by-step diagrammatic transformation from the triangle ladder diagram to the half-diamond diagrams.

S2 Open Access 2008
Open string engineering of D-brane geometry

I. Park

One-loop scattering on a stack of D3 branes was considered in arXiv:0801.0218 [hep-th]. Divergence was found and its cancelation mechanism was proposed, wherein it was conjectured that the D-brane geometry be introduced in the form of counter vertex operators. Here we verify the conjecture at the first few leading orders in an expansion method that we call large-r0 expansion. We comment on the relation with the Fischler-Susskind mechanism and discuss the implications of our result for AdS/CFT.

23 sitasi en Physics
S2 Open Access 2008
Octonions, G(2) and generalized Lie 3-algebras

M. Yamazaki

Abstract We construct an explicit example of a generalized Lie 3-algebra from the octonions. In combination with the result of [S. Cherkis, C. Saemann, arXiv: 0807.0808 [hep-th]], this gives rise to a three-dimensional N = 2 Chern–Simons-matter theory with exceptional gauge group G 2 and with global symmetry SU ( 4 ) × U ( 1 ) . This gives a possible candidate for the theory on multiple M2-branes with G 2 gauge symmetry.

23 sitasi en Physics
arXiv Open Access 2008
Refined BPS state counting from Nekrasov's formula and Macdonald functions

Hidetoshi Awata, Hiroaki Kanno

It has been argued that the Nekrasov's partition function gives the generating function of refined BPS state counting in the compactification of M theory on local Calabi-Yau spaces. We show that a refined version of the topological vertex we proposed before (hep-th/0502061) is a building block of the Nekrasov's partition function with two equivariant parameters. Compared with another refined topological vertex by Iqbal-Kozcaz-Vafa (hep-th/0701156), our refined vertex is expressed entirely in terms of the specialization of the Macdonald symmetric functions which is related to the equivariant character of the Hilbert scheme of points on C^2. We provide diagrammatic rules for computing the partition function from the web diagrams appearing in geometric engineering of Yang-Mills theory with eight supercharges. Our refined vertex has a simple transformation law under the flop operation of the diagram, which suggests that homological invariants of the Hopf link are related to the Macdonald functions.

S2 Open Access 2007
DBI Global Strings

S. Sarangi

In this note we present global string solutions which are a generalization of the usual field theory global vortices when the kinetic term is DBI. Such vortices can result from the spontaneous symmetry breaking in the potential felt by a D3-brane. In a previous paper (hep-th/0706.0485), the DBI instanton solution was constructed which develops a ``wrinkle'' for stringy heights of the potential. A similar effect is also seen for the DBI vortex solution. The wrinkle develops for stringy heights of the potential. One recovers the usual field theory global string for substringy potentials. As an example of the symmetry breaking, we consider a mobile D3-brane on the warped deformed conifold. Symmetry breaking can occur if the structure of the vacuum manifold of the potential for the D3-brane changes as it moves through the throat region.

25 sitasi en Physics
S2 Open Access 2007
Consistent de Sitter string vacua from Kähler stabilization and D‐term uplifting

S. Parameswaran, A. Westphal

In this note, we review our construction of de Sitter vacua in type IIB flux compactifications, in which moduli stabilization and D‐term uplifting can be combined consistently with the supergravity constraints. Here, the closed string fluxes fix the dilaton and the complex structure moduli while perturbative quantum corrections to the Kähler potential stabilize the volume Kähler modulus in an AdS4‐vacuum. Then, magnetized D7‐branes provide consistent supersymmetric D‐term uplifting towards dS4. Based on hep‐th/0602253.

23 sitasi en Physics
S2 Open Access 2007
Half-BPS SU(N) correlators in = 4 SYM

T. Brown

In this note we study half-BPS operators in = 4 super Yang-Mills for gauge group SU(N) at finite N. In particular we elaborate on the results of hep-th/0410236, providing an exact formula for the null basis operators algorithmically constructed there. For gauge groups U(N) and SU(N) we show that this basis is dual to the basis of multi-trace operators with respect to the two point function. We use this to extend the results of hep-th/0611290 concerning factorisation and probabilities from U(N) to SU(N). We also give a construction for a separate diagonal basis of the SU(N) operators in terms of the higher Hamiltonians of the complex matrix model reduction of this sector.

23 sitasi en Physics
S2 Open Access 2007
On Relationships among Chern-Simons Theory, BF Theory and Matrix Model

T. Ishii, Goro Ishiki, Kazutoshi Ohta et al.

Chern-Simons theory on a U(1) bundle over a Riemann surface \Sigma_g of genus g is dimensionally reduced to BF theory with a mass term, which is equivalent to the two-dimensional Yang-Mills on \Sigma_g. We show that the former is inversely obtained from the latter by the extended matrix T-duality developed in hep-th/0703021. For the case of g=0 (i.e. S^2), the U(1) bundle represents the lens space S^3/Z_p. We find that in this case both the Chern-Simons theory and the BF theory with the mass term are realized in a matrix model. We also construct Wilson loops in the matrix model that correspond to those in the Chern-Simons theory on S^3.

23 sitasi en Physics
arXiv Open Access 2007
On the Singularities of the Magnon S-matrix

Nick Dorey, Diego M. Hofman, Juan Maldacena

We investigate the analytic structure of the magnon S-matrix in the spin-chain description of planar ${\cal N}=4$ SUSY Yang-Mills/$AdS_{5}\times S^{5}$ strings. Semiclassical analysis suggests that the exact S-matrix must have a large family of poles near the real axis in momentum space. In this article we show that these are double poles corresponding to the exchange of pairs of BPS magnons. Their locations in the complex plane are uniquely fixed by the known dispersion relation for the BPS particles. The locations precisely agree with the recent conjecture for the $S$ matrix by Beisert, Hernandez, Lopez, Eden and Staudacher (hep-th/0609044 and hep-th/0610251). These poles do not signal the presence of new bound states. In fact, a certain non-BPS localized classical solution, which was thought to give rise to new bound states, can actually decay into a pair of BPS magnons.

arXiv Open Access 2007
Gravi-Leptogenesis: Leptogenesis from Gravity Waves in Pseudo-scalar Driven Inflation Models

S. H. Alexander, M. Peskin, M. M. Sheikh-Jabbari

In this talk we present a mechanism for leptogenesis which is based on gravity waves produced during inflation. We show that when inflation is driven by a pseudo-scalar field the metric perturbations generated during inflation can become birefringent, therefore giving a non-vanishing contribution to the gravitational triangle anomaly and sourcing lepton anti-lepton asymmetry. As this asymmetry is sourced by the fields which are active during inflation, it is not washed out or diluted by inflation. The amount of matter asymmetry generated in our model can be of realistic size for the parameters within the range of some inflationary scenarios and grand unified theories. This talk is based on Ref.[1] which has appeared on the arXiv as hep-th/0403069.

en hep-ph, gr-qc
arXiv Open Access 2007
Gauge Theory Duals of Cosmological Backgrounds and their Energy Momentum Tensors

Adel Awad, Sumit R. Das, K. Narayan et al.

We revisit Type IIB supergravity backgrounds with null and spacelike singularities with natural gauge theory duals proposed in {\tt hep-th/0602107} and {\tt hep-th/0610053}. We show that for these backgrounds there are always choices of the boundaries of these deformed $AdS_5 \times S^5$ space-times, such that the dual gauge theories live on {\it flat} metrics and have space-time dependent couplings. We present a new time dependent solution of this kind where the effective string coupling is always bounded and vanishes at a spacelike singularity in the bulk, and the space-time becomes $AdS_5 \times S^5$ at early and late times. The holographic energy momentum tensor calculated with a choice of flat boundary is shown to vanish for null backgrounds and to be generically non-zero for time dependent backgrounds.

arXiv Open Access 2007
Gauge k-vortices

E. Babichev

We consider gauge vortices in symmetry breaking models with a non-canonical kinetic term. This work extends our previous study on global topological k-defects (hep-th/0608071), including a gauge field. The model consists of a scalar field with a non-canonical kinetic term, while for the gauge field the standard form of its kinetic term is preserved. Topological defects arising in such models, k-vortices, may have quite different properties as compared to ``standard'' vortices. This happens because an additional dimensional parameter enters the Lagrangian for the considered model -- a ``kinetic'' mass. We briefly discuss possible consequences for cosmology, in particular, the formation of cosmic strings during phase transitions in the early universe and their properties.

en hep-th, astro-ph
S2 Open Access 2001
De Sitter space from M-theory?

A. Chamblin, N. Lambert

Abstract In this note we study a massive IIA supergravity theory obtained in hep-th/9707139 by compactification of M-theory. We point out that de Sitter space in arbitrary dimensions arises naturally as the vacuum of this theory. This explicitly shows how de Sitter space can be embedded into eleven-dimensional supergravity. In addition we discuss the novel way in which this theory avoids various ‘no-go theorems’ which assert that de Sitter space is not a consistent vacua of eleven-dimensional supergravity theory. We also point out that the eight-branes of this theory, which couple electrically to the ten-form, will typically sweep out de Sitter world-volumes.

32 sitasi en Physics
S2 Open Access 2002
Z k string fluxes and monopole confinement in non-Abelian theories

M. Kneipp

Recently (hep-th/0104171) we considered N=2 super Yang-Mills with a N=2 mass breakingn term and showed the existence of BPS Z_{k}-string solutions for arbitrary simple gauge groups which are spontaneously broken to non-Abelian residual gauge groups. We also calculated their string tensions exactly. In doing so, we have considered in particular the hypermultiplet in the same representation as the one of a diquark condensate. In the present work we analyze some of the different phases of the theory and find that the magnetic fluxes of the monopoles are multiple of the fundamental Z_{k}-string flux, allowing for monopole confinement in one of the phase transitions of the theory. We also calculate the threshold length for a string breaking. Some of these confining theories can be obtained by adding a N=0 deformation term to N=2 or N=4 superconformal theories.

31 sitasi en Physics
S2 Open Access 2001
A holographic interpretation of asymptotically de Sitter spacetimes

A. Medved

One of the remarkable outcomes of the AdS/CFT correspondence has been the generalization of Cardy's entropy formula for arbitrary dimensionality, as well as a variety of anti-de Sitter scenarios. More recently, related work has been done in the realm of asymptotically de Sitter backgrounds. Such studies presume a well-defined dS/CFT duality, which has not yet attained the credibility of its AdS analogue. In this paper, we derive and interpret generalized forms of the Cardy entropy for a selection of asymptotically de Sitter spacetimes. These include the Schwarzschild–de Sitter black hole (as a review of Preprint hep-th/0112093), the Reissner–Nordstrom–de Sitter black hole and a special class of topological de Sitter solutions. Each of these cases is found to have interesting implications in the context of the proposed correspondence.

30 sitasi en Physics

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