Mritunjay Verma's research while affiliated with University of Southampton and other places

Publications (19)

Preprint
Full-text available
In Bosonic, Heterotic and Type II theories, by employing soft theorems and string techniques, we analyze the gyromagnetic ratios of massive high spin particles coupled to Abelian gauge fields arising from the compactification of the metric and Kalb-Ramond fields. We derive a universal form for such couplings showing that mixed symmetry states of th...
Article
Full-text available
A bstract We analyze Bosonic, Heterotic, and Type II string theories compactified on a generic torus having constant moduli. By computing the hamiltonian giving the interaction between massive string excitations and U(1) gauge fields arising from the graviton and Kalb-Ramond field upon compactification, we derive a general formula for such coupling...
Preprint
Full-text available
We analyze Bosonic, Heterotic, and Type II string theories compactified on a generic torus having constant moduli. By computing the hamiltonian giving the interaction between massive string excitations and $U(1)$ gauge fields arising from the graviton and Kalb-Ramond field upon compactification, we derive a general formula for such couplings that t...
Article
We analyze the single subleading soft graviton theorem in (d + 1) dimensions under compactification on S1. This produces the single soft theorems for the graviton, vector and scalar fields in d dimension. For the compactification of 11-dimensional supergravity theory, this gives the soft factorization properties of the single graviton, dilaton and...
Article
Full-text available
A bstract We analyze the single subleading soft graviton theorem in ( d + 1) dimensions under compactification on S ¹ . This produces the single soft theorems for the graviton, vector and scalar fields in d dimension. For the compactification of 11-dimensional supergravity theory, this gives the soft factorization properties of the single graviton,...
Article
Full-text available
We construct Lorentz invariant and gauge invariant 1PI effective action for closed and open superstrings and demonstrate that it satisfies the classical BV master equation. We also construct the quantum master action for this theory satisfying the quantum BV master equation and generalize the construction to unoriented theories. The extra free fiel...
Preprint
We analyze the single subleading soft graviton theorem in $(d+1)$ dimensions under compactification on $S^1$. This produces the single soft theorems for the graviton, vector and scalar fields in $d$ dimension. For the compactification of $11$-dimensional supergravity theory, this gives the soft factorization properties of the single graviton, dilat...
Preprint
We construct Lorentz invariant and gauge invariant 1PI effective action for closed and open superstrings and demonstrate that it satisfies the classical BV master equation. We also construct the quantum master action for this theory satisfying the quantum BV master equation and generalize the construction to unoriented theories. The extra free fiel...
Article
Full-text available
A bstract Same amplitudes evaluated independently using RNS and pure spinor formalism are expected to agree. While for massless states, this fact has been firmly established, for massive states such an explicit check has been lacking so far. We compute all massless-massless-massive 3-point functions in open supertrings in pure spinor formalism for...
Preprint
Full-text available
Same amplitudes evaluated independently using RNS and pure spinor formalism are expected to agree. While for massless states, this fact has been firmly established, for massive states such an explicit check has been lacking so far. We compute all massless-massless-massive 3-point functions in open supertrings in pure spinor formalism for the first...
Article
Full-text available
A bstract 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 $$ \mathcal{N}=1 $$ N = 1 superfields describing the massive supermultiplet which appear in the uni...
Article
Full-text available
A bstract We define Mellin amplitudes for the fermion-scalar four point function and the fermion four point function. The Mellin amplitude thus defined has multiple components each associated with a tensor structure. In the case of three spacetime dimensions, we explicitly show that each component factorizes on dynamical poles onto components of th...
Article
Full-text available
In arXiv:1707.06803 we derived the subleading multiple soft graviton theorem in a generic quantum theory of gravity for arbitrary number of soft external gravitons and arbitrary number of finite energy external states carrying arbitrary mass and spin. In this paper we verify this explicitly using the CHY formula for tree level scattering amplitudes...
Article
Full-text available
We derive the subleading soft graviton theorem in a generic quantum theory of gravity for arbitrary number of soft external gravitons and arbitrary number of finite energy external states carrying arbitrary mass and spin. Our results are valid to all orders in perturbation theory when the number of non-compact space-time dimensions is six or more,...
Article
Full-text available
We provide the covariant superspace equations that are sufficient to determine the complete $\theta$ expansion of the vertex operator of the open string massive states with $(mass)^2=1/\alpha'$ in pure spinor formalism of superstring theory. These equations get rid of the redundant degrees of freedom in superfields and are consistent with the BRST...
Article
We review recent developments in the construction of heterotic and type II string field theories and their various applications. These include systematic procedures for determining the shifts in the vacuum expectation values of fields under quantum corrections, computing renormalized masses and S-matrix of the theory around the shifted vacuum and a...
Article
We explore the connection between the operator product expansion (OPE) in the boundary and worldsheet conformal field theories in the context of AdS$_{d+1}$/CFT$_d$ correspondence. Considering single trace scalar operators in the boundary theory and using the saddle point analysis of the worldsheet OPE [1], we derive an explicit relation between OP...
Article
We explore the Mellin representation of correlation functions in conformal field theories in the weak coupling regime. We provide a complete proof for a set of Feynman rules to write the Mellin amplitude for a general tree level Feynman diagram involving only scalar operators. We find a factorised form involving beta functions associated to the pro...
Article
Full-text available
In a metastable de Sitter space any object has a finite life expectancy beyond which it undergoes vacuum decay. However, by spreading into different parts of the universe which will fall out of causal contact of each other in future, a civilization can increase its collective life expectancy, defined as the average time after which the last settlem...

Citations

... Massive higher-spin particles in flat space are subject to no-go theorems and high-energy pathologies (see for example refs. [96,97]), hence studying massive string states offered valuable insight on how such issues can be circumvented [98][99][100][101][102]. Exploring the high energy regime, where the higher-spin tower becomes most relevant, also leads to interesting observations that hint to a spontaneous-symmetry-breaking-like mechanism responsible for the particles' mass [89,[103][104][105][106][107][108][109][110][111][112][113][114]. ...
... Such a theorem is also used to show that the effect of attaching a low energy particle to a scattering amplitude is equivalent to multiplying a soft factor to the amplitude, also known as the Weinberg factors. With regard to the in-depth understanding of the factorization, numerous works have been carried out in which such behaviors similarity can be observed in a variety of theories for the low energy limit of massless particles such as photon [2,3,4], gluon [5,6], and gravitons [1,7,8]. ...
... Over the years, we have understood many issues regarding the non-perturbative landscape of SFT classical solutions and the explicit constructions of complete RNS actions [22][23][24][25][26][27][28]. More recently SFT methods have been used to address non-perturbative Dinstantons corrections to closed string scattering amplitudes [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44], which also provided a first-principle resolution of several world-sheet drawbacks associated with degenerations of Riemann surfaces. ...
... When looking for a well-behaved model of fundamental higher-spin particles that satisfies high-energy unitarity constraints, string theory is a natural place to consider. Various aspects of massive states in string theory have been studied for several decades, including work on properties of the spectrum and vertex operators [69][70][71][72][73][74][75][76], and amplitude computations that probe the interaction of massive and massless string states [77][78][79][80][81][82][83][84][85][86][87][88][89][90][91]. In particular, the interaction of massive string states with gravity was the subject of several studies [92][93][94][95]. ...
... A more direct generalization is to formulate the obtained Lagrangian and amplitudes in pure-spinor superspace, based on massive vertex operators [62][63][64]. Besides manifest spacetime supersymmetry, this gives access to BRSTcohomology methods. ...
... Inequality with external spinning fields Toward application to the CRG conjecture with external photons and gravitons, it is significant to generalize our result to the Mellin amplitudes of external spinning fields [44][45][46][47][48][49]. Recent developments in the flat space limit of the AdS/CFT correspondence for external spinning fields [50][51][52][53][54][55] will be helpful in the generalization. ...
... Nevertheless in the recent years the interest to soft theorems has come back with several new results about sub-and subsub-leading terms beyond the soft leading expression [9][10][11][12][13][14][15][16]. Indeed, many recent works were dedicated on several possible preservation and violation cases of universality (of soft theorems) [17][18][19][20][21][22][23][24][25][26] as well as to the connection of soft theorems with the Bondi-Metzner-Van der Burg-Sachs (BMS) symmetry group of asymptotically-flat space-time metric [27][28][29][30][31][32]. ...
... we adapt a variation of the covariantization prescription originally developed in [44,45] for the soft gravitational background. ...
... Another research direction is the construction of the massive vertex operators. They are known in a flat background [86][87][88][89], but these tecniques have not been used in AdS yet. One difficult is that the masses of the states are very complicated functions of α as the worldsheet theory is interacting. ...
... So far we have kept our investigation limited to the local quantum interaction between matter and the gravitational field-ourĤ int was strictly local. It would be interesting to study what would happen if the locality in the gravitational interaction is abandoned [15,[60][61][62][63]. Giving up local gravitational interaction will help us to further investigate the entanglement in theories beyond GR, and in quantum theories of gravity where nonlocal interactions enter in various manifestations (see [3,[64][65][66]). We can also attempt to compute the entanglement by modifying the graviton propagator in nonperturbative formulations of quantum gravity [67,68]. ...