Thermal sunset diagram for scalar field theories

scalar-tensor theories for traceless matter field

ω(φ) → ∞ limit of scalar tensor theories are studied for traceless matter source. It is shown that the limit ω(φ) → ∞ does not reduce a scalar tensor theory to GR. An exact radiation solution of scalar tensor cosmology under modified Nordtvedt conditions is obtained for flat Friedmann universe. PACS numbers: 04.50. +h

Infrared Properties of Scalar Field Theories

Thermal Renormalons in Scalar Field Theory

In the frame of the scalar theory λφ4, we explore the occurrence of thermal renormalons, i. e. temperature dependent singularities in the Borel plane. Using Thermofield Dynamics, we found in fact a series of singularities of this kind, which are located to the right of the well known zero temperature pole, being therefore of a subleading character in the ambiguity of the Borel sum.

A Weak Gravity Conjecture for Scalar Field Theories

Scalars, such as Higgs and inflaton, play significant roles in both particle physics and cosmology. Recently, Vafa et.al. conjectured an upper bound on the strength of gravity relative to gauge forces in quantum gravity [4]. Their conjecture enriches the criteria of consistent effective field theory proposed in [2, 3]. These criteria help to constrain the string landscape [1] in the vast vacua ...

Algebraic Properties of Thermal Quantum Field Theories

We establish the Schlieder and the Borchers property for thermal field theories. In addition, we provide some information on the commutation and localization properties of projection operators.