Results 21 to 30 of about 462 (74)

Ambitwistor strings in six and five dimensions

Journal of High Energy Physics, 2021
Ambitwistor strings are chiral (holomorphic) strings whose target is the space of complex null geodesics, ambitwistor space. We introduce twistor representations of ambitwistor space in 6 and 5 dimensions.
Yvonne Geyer, Lionel Mason, David Skinner   +2 more
doaj   +1 more source

Integrated massive vertex operator in pure spinor formalism

Journal of High Energy Physics, 2018
We construct the integrated vertex operator for the first massive states of open superstrings with (mass)2 = 1/α ′ in the pure spinor formalism of the superstring theory. This vertex operator is expressed in terms of the ten dimensional N = 1 $$ \mathcal{
Subhroneel Chakrabarti, Sitender Pratap Kashyap, Mritunjay Verma   +2 more
doaj   +1 more source

Color-kinematics dual representations of one-loop matrix elements in the open-superstring effective action

Journal of High Energy Physics, 2023
The α ′-expansion of string theory provides a rich set of higher-dimension operators, indexed by ζ values, which can be used to study color-kinematics duality and the double copy. These two powerful properties, actually first noticed in tree-level string
Alex Edison, Micah Tegevi
doaj   +1 more source

Theta expansion of first massive vertex operator in pure spinor

Journal of High Energy Physics, 2018
We provide the covariant superspace equations that are sufficient to determine the complete θ expansion of the vertex operator of the open string massive states with (mass)2 = 1/α′ in pure spinor formalism of superstring theory.
Subhroneel Chakrabarti, Sitender Pratap Kashyap, Mritunjay Verma   +2 more
doaj   +1 more source

A Note on the dS Swampland Conjecture, Non‐BPS Branes and K‐Theory

Fortschritte der Physik, Volume 67, Issue 11, November 2019., 2019
Abstract We point out that the de Sitter swampland conjecture would be falsified if classical fluxed Type IIA orientifold vacua with a single non‐BPS D7‐brane were indeed part of the string theory landscape. In other words, the dS swampland conjecture implies the cancellation of K‐theory charges on a compact space.
Ralph Blumenhagen, Max Brinkmann, Andriana Makridou   +2 more
wiley   +1 more source

Integrating three-loop modular graph functions and transcendentality of string amplitudes

Journal of High Energy Physics, 2022
Modular graph functions (MGFs) are SL(2, ℤ)-invariant functions on the Poincaré upper half-plane associated with Feynman graphs of a conformal scalar field on a torus.
Eric D’Hoker, Nicholas Geiser
doaj   +1 more source

The Landscape, the Swampland and the Era of Precision Cosmology

Fortschritte der Physik, Volume 67, Issue 1-2, January-February 2019., 2019
Abstract We review the advanced version of the KKLT construction and pure de Sitter supergravity, involving a nilpotent multiplet, with regard to various conjectures that de Sitter state cannot exist in string theory. We explain why we consider these conjectures problematic and not well motivated, and why the recently proposed alternative string theory
Yashar Akrami, Renata Kallosh, Andrei Linde, Valeri Vardanyan   +3 more
wiley   +1 more source

Modular graph functions and odd cuspidal functions. Fourier and Poincaré series

Journal of High Energy Physics, 2019
Modular graph functions are SL(2, ℤ)-invariant functions associated with Feynman graphs of a two-dimensional conformal field theory on a torus of modulus τ. For one-loop graphs they reduce to real analytic Eisenstein series. We obtain the Fourier series,
Eric D’Hoker, Justin Kaidi
doaj   +1 more source

CCNV Space‐Times as Potential Supergravity Solutions

Advances in Mathematical Physics, Volume 2018, Issue 1, 2018., 2018
It is of interest to study supergravity solutions preserving a nonminimal fraction of supersymmetries. A necessary condition for supersymmetry to be preserved is that the space‐time admits a Killing spinor and hence a null or time‐like Killing vector field.
A. Coley, D. McNutt, N. Pelavas, Eugen Radu   +3 more
wiley   +1 more source

Calabi‐Yau Manifolds, Hermitian Yang‐Mills Instantons, and Mirror Symmetry

Advances in High Energy Physics, Volume 2017, Issue 1, 2017., 2017
We address the issue of why Calabi‐Yau manifolds exist with a mirror pair. We observe that the irreducible spinor representation of the Lorentz group Spin(6) requires us to consider the vector spaces of two forms and four forms on an equal footing. The doubling of the two‐form vector space due to the Hodge duality doubles the variety of six‐dimensional
Hyun Seok Yang, Sangheon Yun, Anna Cimmino   +2 more
wiley   +1 more source